bluuebunny/crossref_metadata_2025 huggingface dataset:
Aortic root dilatation and mitral valve prolapse in Marfan's syndrome: an ECHOCARDIOgraphic study.
Authors: Brown O R , DeMots H , Kloster F E , Roberts A , Menashe V D , Beals R K
Published: June 2012

Echocardiographic and phonocardiographic findings in 35 patients with Marfan's Syndrome and ten patients without Marfan's or other clinically apparent connective tissue disorders but with angiographic and echocardiographic evidence of mitral prolapse are reported and compared. Echocardiography revealed aortic root dilatation and/or mitral valve prolapse in 97% of the patients with Marfan's Syndrome. Aortic root dilatation was found in 60% of this group (74% of males, 33% of females) while mitral valve prolapse was found in 91% (87% of males, 100% of females). The incidence of aortic dilatation and mitral prolapse in patients with Marfan's syndrome was essentially equal in children and adults of the same sex. None of the nine adults or one child with mitral prolapse but without evidence of Marfan's Syndrome or other clinically apparent connective tissue disorder had aortic root enlargement. Ausculatory examination and phnocardiography revealed abnormalities in 54% of the patients with Marfan's Syndrome. Aortic regurgitation was found in 23% of this group (35% of males, 0% of females) while mitral regurgitation and/or mitral clicks were found in 46% (39% of males, 58% of females). Aortic regurgitation was much more frequent in adult males with Marfan's Syndrome (7/14, 50%) than male children (1/9, 11%), while the incidence of abnormal mitral sounds was essentially the same in adults (33% of males, 60% of females) and children (43% of males, 57% of females) of the same sex with Marfan's Syndrome. Abnormal mitral sounds were more frequent in patients without Marfan's who had mitral prolapse (90%) than in those with Marfan's (46%). It appears that cardiac abnormalities are a consistent manifestation of Marfan's Syndrome and that ultrasound is a more sensitive indicator of these abnormalities in such patients than ausculation or phonocardiography.
Unexpected cardiac arrest in patients after surgical correction of tetralogy of Fallot.
Authors: James F W , Kaplan S , Chou T C
Published: June 2012

Four of 220 patients without bifasicular block (complete right bundle branch block and left anterior hemiblock) or transient complete heart block immediately after surgery had an unexpected cardiac arrest one to 15 years after satisfactory surgical repair of tetralogy of Fallot. The postoperative electrocardiograms (ECG) revealed complete right bundle branch block in two patients and no intraventricle conduction abnormality in two patients. Each of the four patients had premature ventricular contractions on previous postoperative ECG. The cardiac arrest occurred during normal activity in three patients and mild exercise in one. Following the cardiac arrest, three patients died and one patient survived. Eighteen months before the cardiac arrest, the survivor had a stress test which revealed multifocal premature ventricular contractions with short bursts of ventricular tachycardia after exercise. This ventricular arrhythmia was suppressed with quinidine therapy. Although complete heart block cannot be excluded in these four patients, we reasoned that the cardiac arrests were probably preceded by ventricular tachyarrhythmia. Because of this experience, we believe that any patient who has had intraventricular surgery should be evaluated for ventricular arrhythmia. If frequent premature ventricular contractions or serious ventricular arrhythmias are documented, we seriously consider antiarrhythmic therapy in an attempt to prevent ventricular tachyarrhythmias and sudden death.
Long-term treatment of severe hypertension with minoxidil, propranolol and furosemide.
Authors: Wilburn R L , Blaufuss A , Bennet C M
Published: June 2012

Thirteen patients with severe hypertension were treated with combined minoxidil, propranolol, and furosemide (mean daily doses 33 mg, 475 mg, and 578 mg, respectively) for nine to twenty-five months (mean 13.8). Average mean blood pressure while on aggressive therapy with conventional medication was 144 +/- 14 mm Hg; on minoxidil and propranolol it was 108 "/- 10 mm Hg (P less thator to optimum blood pressure control and required large doses of furosemide to control. Propranolol blunted the reflex tachycardia associated with arteriolar dilator therapy but all patients continued with a clinically hyperdynamic circulation. Seven of seven had elevated ejection fractions on echocardiogram, and two of three had elevated cardiac indices. Three of three who had heart catheterization had pulmonary hypertension which was aggravated by exercise. An additional three patients on hydralazine, propranolol, and furosemide also had pulmonary hypertension suggesting this is not unique to minoxidil. Two of thirteen developed pericardial effusions. Renal function improved in three and worsened in three.
Complete interruption of the aortic arch. 1. Characteristic radiographic findings in 21 patients.
Authors: Jaffe R B
Published: June 2012

The radiographs of 21 patients with complete interruption of the aortic arch are reviewed, together with the literature, to emphasize characteristic radiographic features previously not recognized or discussed. In addition to the nonspecific radiologic findings of a left-to-right shunt through the invariably present ventricular septal defect, charateristic and unique features noted on chest radiograph and barium swallow that may suggest the diagnosis prior to catheterization include: a) a midline trachea; b) a hypoplastic ascending aorta with direct vertical ascent toward the neck; c) absence of the aortic "knob;" d) termination of the descending thoracic aortic shadow at the level of the main pulmonary artery; e) a "low arch" on lateral or left anterior oblique projections; and f) absence of the normal aortic impression on the barium-filled esophagus. Rib notching, when present, in association with the above findings indicates a stenotic or closed ductus arteriosus with collateral circulation through intercostal arteries to the descending aorta. The bilateral or unilateral location, right or left side, of the notching is dependent on the site of interruption and origin of the subclavian arteries and may permit differentiation into types and subtypes on chest radiograph.
Observations on patients with primary ventricular fibrillation complicating acute myocardial infarction.
Authors: Lie K I , Wellens H J , Downar E , Durrer D
Published: June 2012

In order to evaluate the events preceding primary ventricular fibrillation (PVF), continuous tape recording was performed in 262 patients consecutively admitted to the hospital within six hours of infarction in whom antiarrhythmic therapy was withheld. Warning arrhythmias (defined as ventricular ectopic beats occurring with a frequency of more than five beats per minute, in runs, falling in the vulnerable phase of the cardiac cycle or being multiformed) were registered in an equal percentage in patients who did or did not develop PVF. Immediately prior to PVF seven patients showed sinus tachycardia, 10 a sinus rate ranging from 60 to 100 beats per minute and two bradycardia due to complete atrioventricular block. The ventricular ectopic beat initiating PVF had a late coupling interval (QR'/QT larger than or equal to 0.85) in 11 patients and a left bundle branch block configuration as frequent as a right bundle branch block. Conclusions: 1) Warning arrhythmias are not considered good criteria for institution of antiarrhythmic therapy in order to prevent PVF. 2) In patients with sinus rhythm there may be an association between heart rate and onset of PVF. 3) The malignancy of a ventricular ectopic beat is not determined by its coupling interval or its configuration.
Demonstration of dual atrioventricular nodal pathways utilizing a ventricular extrastimulus in patients with atrioventricular nodal re-entrant paroxysmal supraventricular tachycardia.
Authors: Wu D , Denes P , Wyndham C , Amat-y-Leon F , Dhingra R C , Rosen K M
Published: June 2012

In patients with atrioventricular (A-V) nodal re-entrant paroxysmal supraventricular tachycardia (PSVT), atrial extrastimulus technique frequently reveals discontinuous A1-A2, H1-H2 curves suggestive of dual A-V nodal pathways. To further test the hypothesis that these curves in fact reflect dual A-V nodal pathways, a ventricular extrastimulus (VS) was coupled either to A2 at a fixed A1-A2 interval which reliably produced an A-V nodal re-entrant atrial echo (E) with a constant A2-E interval in two patients, or to QRS complex (V) during sustained PSVT with a constant E-E interval in one patient. Three response zones were defined: at longer A2-VS or V-VS coupling interval, VS manifested no effect on the timing of E (Zone 1). At closer A2-VS or V-VS coupling interval, VS conducted to the atrium, shortening the apparent A2-E or E-E interval (Zone 2). At shortest A2-VS or V-VS coupling interval, VS was blocked retrogradely, and no E was induced (Zone 3). The ability of VS to preempt control of the atria (Zone 2 response) strongly suggests the presence of dual A-V nodal pathways in these PSVT patients. If only a single pathway were present, VS would of necessity collide with the antegrade impulse and could not reach the atria. The Zone 3 response occurs because of retrograde refractoriness of the fast pathway. Failure of the echo during Zone 3 probably reflects concealed conduction to the fast pathway, or possibly interference in the slow pathway.
Precordial ST-segment mapping 1. Clinical studies in the coronary care unit.
Authors: Madias J E , Venkataraman K , Hodd W B
Published: June 2012

Precordial ST-segment mapping Was applied serially in the coronary care unit for the study of 46 patients with myocardial infarction (MI), using a 49-lead system. Data from the maps were compared with clinical status of patients, conventional ECGs obtained simultaneously, and serum enzyme levels. Stability of the maps over a one hour period was noted in the early phase of admission. However, a drop of 32% of the sum of ST-segment elevations (+sigma ST) was detected in eight patients with uncomplicated anterior MI over the first 24 hours after admission. Extension of infarction was associated with abrupt rise of + sigma ST, and was diagnosed in two cases from maps in the presence of unchanged standard ECGs. The course of ST elevations was followed more accurately by the map than the standard ECG in eight patients. Pericarditis invalidated the technique completely, due to persistent + sigma ST. The standard ECG was superior to the map in following patients with inferior MI. A case of true posterior MI was more accurately delineated by maps of the posterior thorax than by the standard ECG. Intraventricular conduction defects and pacemaking interfered with maps. Early repolarization produced stable maps; however, mapping showed no advantages over the standard ECG. Preinfarction angina can probably be followed by serial mapping of ST-segment depression.
Determinants of reversible asynergy. The native coronary circulation.
Authors: Banka V S , Bodenheimer M M , Helfant R H
Published: June 2012

To evaluate the influence of the native coronary circulation on the reversibility of asynergy, ventriculograms before and after sublingual nitroglycerin were performed in 51 patients with coronary artery disease and asynergy. The severity of stenotic lesions and caliber of the distal coronary vessels were determined by comparison with external catheter tip diameter corrected for magnification. Of 42 asynergic zones associated with larger than or equal to 90% proximal coronary occlusion, 27 (64%) were akinetic or dyskinetic while only 11 of 38 zones (29%) with less than 90% occlusion showed akinesis (P less than 0.005). Twenty-six of the 38 asynergic zones (69%) with less than 90% occlusion were reversible in contrast to 19 of the 42 zones (45%) with larger than or equal to 90% occlusion (P less than 0.05). Coronary collaterals were observed in 23 of 42 (55%) zones with larger than or equal to 90% occlusion in contrast to only 11 of 38 zones (29%) with less than 90% occlusion (P less than 0.05). Of the zones with both greater than or equal to 90% occlusion and collaterals, 74% were reversible, in contrast to only 11% without collaterals (P less than 0.001). Of the asynergic zones without collaterals, 63% with less than 90% occlusion were reversible in contrast to only 11% with larger than or equal to 90% occlusion (P less than 0.001). Pathologic Q waves were associated with 24 of 42 zones (57%) with larger than or equal to 90% occlusion compared to only nine of the 38 zones (24%) with less than 90% occlusion (P less than 0.01). The presence of Q waves was associated with a significant decrease in the incidence of reversibility regardless of the degree of coronary occlusion. Excluding the asynergic zones with either collaterals or Q waves, 79% with less than 90% occlusion were reversible in contrast to only 37% with larger than or equal to 90% coronary occlusion (P less than 0.05). In contrast, the caliber of the distal vessel could not be correlated with either the severity of asynergy or the presence of collaterals and was similar in both reversible and irreversible asynergic zones. In summary, larger than or equal to 90% proximal stenosis is associated with severe asynergy which is less likely to be reversible compared to asynergy associated with less than 90% coronary occlusion. In the presence of larger than or equal to 90% occlusion, coronary collaterals are associated with a significantly higher incidence of reversible asynergy and thus appear to serve a protective function. However, the caliber of the distal vessel per se does not effect the severity or reversibility of asynergy.
Cross-sectional echocardiography in assessing the severity of valvular aortic stenosis.
Authors: Weyman A E , Feigebaum H , Dillon J C , Chang S
Published: June 2012

Real-time, cross-sectional echocardiograms were recorded in 28 consecutive adult patients with valvular aortic stenosis using a high resolution, mechanical sector scanner. Using the cross-sectional technique, the aortic valve orifice diameter was recorded in each of the 28 patients. With M-mode echocardiographic examination of these same patients, this value could be estimated in only 21 of these 28 patients (75%). The maximum aortic valve diameter recorded during the cross-sectional study averaged 7.9 +/- 1.8 mm (range 4-11 mm) in 15 patients with severe aortic stenosis; 11.6 +/- 2.3 mm (range 9-15 mm) in five patients with moderate aortic stenosis; 16.9 +/- 2.0 mm (range 14-20 mm) in eight patients with mild aortic stenosis; and 20.5 +/- 2.8 mm (range 15-26 mm) in 25 patients with no evidence of aortic valve disease. Comparing the means of these groups yielded the following: severe vs moderate P less than 0.005; moderate vs mild P less than 0.001; and mild vs normal P less than 0.001. Although there was some overlap between the individual groups, a clear separation existed between patients with severe and mild aortic stenosis. In addition, the group of patients in whom surgical intervention was recommended was also separated from the other subjects. When the aortic valve orifice was recorded using the M-mode technique, there was also a good correlation with the severity of the stenosis; however, the tendency of the M-mode study to overestimate severity in individual patients with calcific aortic stenosis and to underestimate severity in congenital aortic stenosis was again demonstrated. This study suggests that real-time, high resolution, cross-sectional echocardiography should be valuable in the noninvasive assessment of patients with aortic stenosis.
Regional myocardial function in idiopathic hypertrophic subaortic stenosis. An echocardiographic study.
Authors: Cohen M V , Cooperman L B , Rosenblum R
Published: June 2012

To assess regional contractility in idiopathic hypertrophic subaortic stenosis (IHSS), a primary myopathic disorder with documented hyperdynamic ventricular contractions, systolic wall thickening and velocity of contraction of the septum and left ventricular posterior wall were measured in echocardiograms from 16 patients with IHSS and 16 normal subjects. The average thickening of the normal septum and posterior wall was 75.9+/-8.8% and 84.8+/-6.3%, respectively. The posterior wall in IHSS thickened by 75.1+/-6.8%. None of these values differed significantly. However, the increase in thickness of the IHSS septum averaged 22.5+/-2.4%, significantly less than that of either the IHSS posterior wall or the normal septum. Velocity measurements confirmed the impression of diminished septal function. The mean velocity of normal septal contraction averaged 37.0+/-2.3 mm/sec, normal posterior wall 42.3+/-2.0 mm/sec and IHSS posterior wall 55.7+/-3.5 mm/sec, whereas the septum in IHSS contracted at the rate of 26.0+/-2.5 mm/sec. Thus, the IHSS septum contracted significantly more slowly than the normal septum or IHSS posterior wall. However, the posterior wall velocity in IHSS was significantly more rapid than that measured in normal ventricles--perhaps to compensate for the septum. Normalization of all velocities for left ventricular end-diastolic internal diameter did not alter the sifnificance of the results. Consideration of IHSS as an asymmetric myopathy based on prior observations of predominantly septal hypertrophy and distorted septal cellular architecture is now supported by the above evidence of functional left ventricular asymmetry. Although the total left ventricular function in IHSS may be hyperdynamic, regional function is not uniform. The septum appears to be hypodynamic, while the contractile capacity of the posterior wall is increased.
Temporal heterogeneity of myocardial blood flow in anesthetized dogs.
Authors: Falsetti H L , Carroll R J , Marcus M L
Published: June 2012

Temporal variation in perfusion to small segments of the myocardium was studied in 19 opened-chest dogs. In six control dogs, three or four differently labeled 7-10 mu microspheres were injected simultaneously into the left atrium to assess the variability in measured myocardial perfusion due to the microsphere technique. In 13 other dogs, microspheres were injected four times at 5 minute intervals while various hemodynamics parameters (mean aortic pressure, peak systolic pressure, heart rate, left ventricular end-diastolic pressure, and Vmax) were stable (less than 10% variation in any one parameter). The left ventricles were divided into 96 segments, the mean weight+/- SD of each segment was 0.95+/-0.17 grams. The flow to each segment was expressed as a percent of the mean flow of the three or four measured flows to that segment, and the difference between the largest and the smallest percent of each segment was taken as a measure of the variability of flow to that segment. The average variability of segmental flow (mean +/-SD) when the three to four differently labeled microspheres were injected was 14.0+/-4.7; and the variability when differently labeled microspheres injected sequentially was 31.0+/-10.8% (P less than 0.001). Furthermore, in the sequentially injected animals the magnitude of temporal variation was similar in various subdivisions of the ventricle (layers, walls, apex to base). The mean and standard deviation of the variability of flow to the endo, mid, and epicardial layers were 28.7+/-10.2, 30.0+/-11.3 and 34.5+/-12.4%, respectively. These changes may reflect either spontaneous or local autoregulatory changes in precapillary sphincters or arterioles.
Impairment of myocardial O2 supply due to hyperventilation.
Authors: Neill W A , Hattenhauer M
Published: June 2012

Thirteen patients with ischemic coronary heart disease purposely hyperventilated for seven minutes in order to induce hypocapnic alkalosis. One patient experienced chest pain, and one exhibited chemical signs of myocardial hypoxia. Heart rate, blood pressure and myocardial O2 consumption did not change significantly. Coronary blood flow decreased and coronary (a-v)O2 difference widened. Since the alkalosis increased the blood O2 affinity, the fall in PO2 in coronary venous blood was proportionately even greater than the fall in O2 concentration. Thus, hypocapnic alkalosis due to hyperventilation interferes with myocardial O2 supply by 1) coronary vasoconstriction and 2) increased O2 affinity of blood.
Clinical and hemodynamic results of mitral valve replacement with autologous fascia lata grafts. Studies in patients with competent prostheses.
Authors: Taylor S H , Galvin M C , Pakrashi B C , Tulpule A T , Ionescu M I , Whitaker W
Published: June 2012

Nine patients with severe mitral disease were studied before and six months after mitral valve replacement with a three-cusp stented prosthesis using fresh autologous fascia lata tissue. Only patients in whom there was no auscultatory and angiographic evidence of incompetence of the replaced valve were selected for restudy. All patients claimed a marked improvement in their exercise capacity after operation and there was a significant reduction in radiographic heart size. The cardiac output at rest and the response to exercise were both reduced before operation and were unchanged after valve replacement. The elevated pulmonary arterial and wedge pressures were significantly reduced after operation in all patients both at rest and during exercise, but in no instance were the postoperative exercise values within normal limits. Left ventricular end-diastolic pressure was within normal limits at rest and during exercise in all patients after valve replacement but the average pressure gradient across the fascia lata valve was 6+/-1 mm Hg at rest and 18+/-3 mm Hg during exercise. These findings indicate that altough replacement of the diseased mitral valve with a competent fascia lata prosthesis afforded substantial symptomatic relief, reduction of cardiac enlargement and a lowering of the pulmonary vascular pressures, this artificial valve offered a significant obstruction to left ventricular diastolic filling, particularly during exercise.
Correlation of plasma propranolol concentration with therapeutic response in patients with angina pectoris.
Authors: Pine M , Favrot L , Smith S , McDonald K , Chidsey C A
Published: June 2012

The therapeutic response to propranolol was evaluated in patients with documented coronary artery disease at doses varying from 40 to 320 mg/day. Therapeutic response was quantified by evaluating exercise performance on a treadmill and then related to plasma propranolol concentration. Plasma propranolol was defined in terms of beta-adrenergic blockade by comparison with dose (concentration) response curves in normal subjects. Individual therapeutic benefit occurred at doses which averaged 144 +/- 21 mg/day and at concentrations which averaged 30 +/- 7 ng/ml. There was a wide variation between both dose and concentration among the patients at maximum therapeutic response, but when the plasma propranolol was related to pharmacologic activity, the maximum therapeutic response was observed between 64 to 98% of total blockade. Despite the increased exercise performance in these patients, the double product of heart rate and systolic blood pressure was always less, suggesting either an alteration of the relation between myocardial oxygen consumption and the double product during propranolol or a reduction on oxygen delivery to the myocardium as the result of beta-adrenergic blockade of the coronary vasculature.
Congenital heart malformations associated with disproportionate ventricular septal thickening.
Authors: Maron B J , Edwards J E , Ferrans V J , Clark C E , Lebowitz E A , Henry W L , Epstein S E
Published: June 2012

Asymmetric septal hypertrophy, or ASH, is a genetically determined myocardial disorder that is transmitted as an autosomal dominant trait. ASH is characterized by a disproportionately thickened ventricular septum that contains numerous hypertrophied, bizarrely-shaped and disorganized cardiac muscle cells. Disproportionate hypertrophy of the ventricular septum has also been observed in association with certain congenital cardiac malformations. To determine whether such congenital cardiac malformations are part of the disease spectrum of genetically determined ASH, cardiac pathologic observations were made in eight patients with disproportionate septal thickening (ventricular septal to posterobasal left ventricular free wall thickness ratios of 1.5 to 2.5) and the following three categories of associated lesions: 1) parachute deformity of the mitral valve (occurring either as an isolated lesion or with ventricular septal defect, coarctation of the aorta, supravalvular ring of the left atrium, or double outlet right ventricle); 2) complete interruption of the aortic arch; and 3) ventricular septal defect. The arrangement of cardiac muscle cells in the disproportionately thickened ventricular septum was normal in six of the eight patients; in the other two patients (one with parachute deformity of the mitral valve and one with ventricular septal defect) numerous bundles of hypertrophied cardiac muscle cells were interlaced in a disorganized fashion among more normally arranged bundles of cells. First degree relatives of six of the eight patients were studied by echocardiography and found to have normal ventricular wall thicknesses and septal-free wall ratios. It is concluded that disproportionate ventricular septal thickening may occur in patients with a variety of congenital heart malformations, but that such a finding is not necessarily a manifestation of the disease spectrum of genetically determined ASH.
Ventricular arrhythmias in the late hospital phase of acute myocardial infarction. Relation to left ventricular function detected by gated cardiac blood pool scanning.
Authors: Schulze R A , Rouleau J , Rigo P , Bowers S , Strauss H W , Pitt B
Published: June 2012

Abnormalities of left ventricular function and extent of myocardial infarction were studied in relation to prevalence of late ventricular premature contractions (VPCs) in 36 patients in the convalescent stage of acute myocardial infarction (MI). Left ventricular ejection fraction (EF) and percent akinesis (%A) were calculated from gated cardiac blood pool scans; myocardial infarct size was estimated from peak CPK values; and VPCs were detected by 24 hour ambulatory ECGs 2-4 weeks following hospitalization for acute MI. Twenty-two patients had either zero (class 0) or less than 30/hour unifocal VPCs (class I). Fourteen patients had greater than 30/hour unifocal (class II), multifocal (class III) or coupled VPCs (class IV), including ventricular tachycardia. Thirteen of 14 class II-IV patients had EF less than 40% compared with only 8 of 22 class 0-I patients. Class II-IV patients had significantly lower mean EF (30.5 +/- 2.3 SE to 49.6 +/- 4.0) P less than 0.01, higher mean %A (28.1 +/- 2.2 to 16.9 +/- 3.7) P less than 0.05, and higher mean peak CPK (1350 +/- 187 to 721 +/- 155) P less than 0.05 than class 0-I patients. These data suggest that VPCs may not be an independent risk factor for sudden cardiac death in the convalescent phase of MI.
Diagnostic accuracy of ambulatory ECG monitoring in ischemic heart disease.
Authors: Stern S , Tzivoni D , Stern Z
Published: June 2012

Fifty patients with precordial pain were evaluated by 24 hour ambulatory ECG monitoring during normal everyday activities, and by coronary arteriography. The monitoring was regarded as positive if deviation of the ST segment of 1 mm or more from the resting pattern was observed, or if major T wave inversion occurred. Comparison of the results of the two tests showed a good correlation. Among the 32 patients with positive abnormalities on ECG monitoring, 28 had severe coronary disease (greater than 60% obstruction). Among the 18 patients with negative monitoring, only three had severe coronary disease. All seven patients with major T inversion had significant coronary obstruction. The type of chest pain and the resting ECG were less indicative of coronary pathology. The good correlation demonstrated between the ambulatory ECG monitoring and coronary arteriograms validates the monitoring as a reliable tool for uncovering latent ischemic heart disease (IHD) and for evaluation of patients with established IHD.
Hemodynamics and annuloplasty in isolated mitral regurgitation in children.
Authors: Sulayman R , Mathew R , Thilenius O G , Replogle R , Arcilla R A
Published: June 2012

Isolated mitral insufficiency in children is quantitated angiographically by comparing the stroke volumes of the right ventricle and left ventricle. The disease results in greater enlargement of the left atrium than of the left ventricle and is accompanied by a significant increase in left atrial "distensibility." Right and left heart pressures may be normal or may be increased; they tend to be elevated in the group with regurgitant fractions of over 50%. Annuloplasty results in marked clinical and hemodynamic improvement and may even be corrective.
The incidence and clinical implications of coronary artery spasm.
Authors: Chahine R A , Raizner A E , Ishimori T , Luchi R J , McIntosh H D
Published: June 2012

The total incidence of coronary artery spasm during coronary angiography has been reported to be between 0.26% and 0.93%. The rarity of this phenomenon has been invoked to minimize its clinical significance. Review of a one-year experience in our catheterization laboratory showed that coronary spasm occurred in eight of 274 coronary angiograms (2.93%). In three instances, spasm could not be ascribed to catheter tip irrigation, and was considered to be spontaneous. Since multiple factors during coronary arteriography might inhibit the occurrence of coronary spasm, it is believed that the incidence of spontaneous spasm may be higher than can be documented during angiography. Coronary spasm may have important clinical significance in various chest pain syndromes and greater methodical attention should be directed toward this phenomenon.
Electrophysiologic characteristics of Ebstein's anomaly of the tricuspid valve.
Authors: Kastor J A , Goldreyer B N , Josephson M E , Perloff J K , Scharf D L , Manchester J H , Shelburne J C , Hirshfeld J W
Published: June 2012

Electrophysiologic characteristics of five patients with Ebstein's anomaly of the tricuspid valve were defined with studies using luminal intracardiac electrode catheters. The diagnosis was made in each case from clinical data and confirmed at cardiac catheterization by the presence of an atrialized right ventricular chamber with atrial mechanical activity and ventricular electrical activity. In three cases intra-right atrial conduction was prolonged (P-A intervals of 50, 50, and 65 msec), a finding which reflected the presence of a characteristically large right atrium. The bundle of His electrogram was recorded in its usual anatomical location. Atrioventricular nodal conduction was prolonged in only one case. Intra-His delay was observed in two cases (bundle of His duration of 30 and 30 msec). Infranodal conduction was prolonged in four cases with H-V intervals of 60, 65, 65, and 80 msec. The anatomical abnormalities were least severe in the only patient with a normal H-V interval (50 msec). The prolonged H-V interval was thought to result from stretching of the conduction system over the atrialized right ventricle (ARV). The late depolarization during the splintered R' of the electrocardiogram found during intracardiac mapping of the ARV in three patients confirms the theory that the ARV produces the "second QRS" typically seen in this anomaly. The ARV was particularly irritable, and ventricular fibrillation was produced in two patients during catheter manipulation in this area. In one case the ARV had a shorter refractory period than the body of the right ventricle. Re-entrant supraventricular tachycardia was induced in the only patient with Wolff-Parkinson-White syndrome. In addition to the previously recognized electrophysiologic features reconfirmed here, patients with Ebstein's anomaly of the tricuspid valve usually have: normal position of the bundle of His, prolonged intra- right atrial conduction, prolonged infranodal conduction, and irritable ARV with delayed activation.
The displacement cardiograph. A noninvasive technique for recording myocardial wall motion.
Authors: Gay T C , Vas R , Pittman D E , Joyner C R
Published: June 2012

The displacement cardiograph (DCG) is a noninvasive device employing an electromagnetic field to record tissue motion within the body. The sensing coil need not be in contact with the patient since the field penetrates air and stationary tissue without significant distortion. Disturbances in the field with result from ventricular wall motion are electronically converted to an analog output and a pattern inscribed on the paper of a physiological recorder. In an attempt to determine the reliability of the DCG in detecting regional areas of abnormal left ventricular wall motion, displacement cardiograms were obtained from 70 patients who underwent cardiac catheterization and left ventriculography. The DCG interpretations were in agreement with the ventriculographic picture of left ventricular wall motion in 67 of the 70 patients. There were two false positive and one false negative DCG diagnoses. The results indicate that the DCG can be employed as a reliable noninvasive method for repetitive assessment of the pattern of contraction of the anterior, anterolateral and posterior left ventricular wall.
Morphological development of the pulmonary vascular bed in fetal lambs.
Authors: Levin D L , Rudolph A M , Heymann M A , Phibbs R H
Published: June 2012

The morphological development that accompanies increasing pulmonary blood flow and decreasing pulmonary vascular resistance with advancing gestational age has not been delineated. To study this point we developed a method of comparing pulmonary arterial vessels of the same generations in fetal lambs. Pulmonary arteries were perfused with glutaraldehyde solution at pressures appropriate for gestational age and then injected with an India ink-gelatin-Micropaque mixture. Using the dissecting microscope and serially prepared sections we studied successively smaller generations of arteries. We assessed the medial width/external diameter ratio in a total of 825 vessels from six fetal lambs of 85 to 140 days gestation. In fifth generation, or resistance vessels, this ratio remained constant over the gestational period studied (N = 529, Y = 0.16, slope = 0.0003). We measured the volume of 17-34 randomly selected sections from each of the six fetuses, counted the total number of fifth and sixth generation vessels in these sections, and calculated the total number of these vessels per right lung. This number increased from 0.10 X 10(6) to 4.08 X 10(6) with increasing gestational age. The number of vessels per unit volume increased from 7.2 X 10(3)/ml to 61.8 X 10(3)/ml or right lung over this gestational period. The results indicate that increased pulmonary blood flow and decreased pulmonary vascular resistance with advancing gestation are due to an increase in the total number of vessels and increased vasomotor reactivity is related to an increase in the total amount of smooth muscle while the thickness of muscle in individual vessels remains constant.
Coronary risk factors in a community. Findings in Tecumseh, Michigan.
Authors: Ostrander L D , Lamphiear D E
Published: June 2012

In the Tecumseh study population examined from 1967 through 1969, 1457 men and 1607 women were separated into young (20-39 years), middle (40-54 years), and old (past 55 years) age categories. A subset of the study population, 183 men and 200 women who were repeatedly hyperglycemic according to a modified glucose tolerance test, were divided into the same age groups. Means and standard deviations of adiposity index, serum cholesterol, serum triglyceride, blood glucose, and systolic blood pressure were calculated for the total population and hyperglycemics. Correlation coefficients were determined for the relationship between adiposity index and each of the other variables and between paired variables exclusive adiposity index. Correlation coefficients for the latter relationships were recalculated after adjustment for the effect of adiposity. Means of variables were higher in middle and older age categories than in young age categories in both sexes, but the greatest incremental increases occurred between the young and middle-aged groups of men and between middle and old age groups among women. Men had significantly higher mean triglyceride and systolic blood pressure values than women in young and middle ages. Except for the cholesterol-triglyceride association, lipids, glucose, and systolic blood pressure were more highly correlated with adiposity than with each other. Correlations between variables were reduced by adjustment for adiposity. Hyperglycemics had higher mean adiposity indexes, serum lipids, and systolic blood pressures and generally higher correlations of variables than the entire study population. Much of the interrelationship of variables among hyperglycemics was associated with adiposity. Among men, higher mean triglyceride and systolic blood pressure levels, more frequent coexistence of risk factors, and a tendency to have large incremental increases in mean variables between young and middle age probably contribute to greater male susceptibility to ischemic heart disease. Levels of variables in the population and aggregation of coronary precursors in individuals are related to adiposity and hyperglycemia.
Dissecting aneurysm of aorta complicating aortic valvular stenosis.
Authors: Fukuda T , Tadavarthy S M , Edwards J E
Published: June 2012

Six cases of classical dissecting aneurysm of the aorta complicating aortic valvular disease in which aortic stenosis was dominant are described. In three of the cases the aortic complication occurred after the natural aortic valve had been replaced by a prosthetic valve. The longest postoperative period was four months. The factor common to all reported cases in our series was cystic medial necrosis of the aorta. The authors agree with the concept of McKusick and associates that aortic dissecting aneurysm complicating aortic valvular disease is an association other than chance and is related to cystic medial necrosis of the aorta. The latter, in turn, is a consequence of the altered hemodynamics of aortic valvular disease, particularly stenosis.
Left ventricular diverticulum and mitral incompetence in asymptomatic children.
Authors: Gueron M , Hirsch M , Opschitzer I , Mogel P
Published: June 2012

Two children with congenital apical left ventricular diverticulum and significant mitral incompetence are reported. The angiographic and anatomic findings of the few previously reported patients with congenital diverticula and aneurysm were analyzed and a new classification differentiating between the two is proposed. The clinical data analyzed in apical diverticula and aneurysm are similar to those patients with anomalous origin of the left coronary artery from the pulmonary artery. Left ventriculography is the best diagnostic tool. The place of surgery in the treatment of the congenital apical diverticula with or without mitral incompetence in asymptomatic children is not clear. Further observations are needed to reveal its natural history.
Histopathology of the conduction system in the sudden infant death syndrome.
Authors: Lie J T , Rosenberg H S , Erickson E E
Published: June 2012

The cause of the sudden infant death syndrome (SIDS, crib death, or cot death) is unknown. Current hypotheses include lability of heart rate and/or rhythm as a pathogenetic factor. The conduction system of 50 infants coming to autopsy were examined by serial sections; the infants were from newborn to two years of age. Twenty-six were SIDS deaths and 24 were explained deaths (ED). The frequency of histologic abnormalities of the specialized tissue was almost identical in both groups of infants. Hemorrhage in or around different parts of the conduction system was present in 27% SIDS and 29% ED. There was no evidence of cell death or degeneration of conduction fibers, nor obstructive lesions of the atrioventricular (A-V) arteries. Apparent moulding of A-V node and His bundle was a universal finding in both SIDS and ED, and consisted of irregular interdigitation of A-V node and His bundle fibers with the myxoid central fibrous body (CFB). Isolated bundles of conduction fibers residing in CFB and membranous ventricular septum were seen in two SIDS, but no direct contact between these fibers and the working myocardium could be identified in serial sections in either case. Without corroborating antemortem electrophysiologic data, the functional significance of morphologic findings in the conduction system of SIDS must remain conjectural.
Effects of the pacing site on A-H conduction and refractoriness in patients with short P-R intervals.
Authors: Aranda J , Castellanos A , Moleiro F , Befeler B
Published: June 2012

His bundle recordings were studied in four patients with short P-R and A-H intervals, and narrow QRS complexes, who had experienced several episodes of supraventricular tachyarrhythmias. The heart was paced from the high right atrium (HRA) and the coronary sinus (CS). In three patients the A-H Wenckebach phenomenon occurred at higher rates (greater than 200 pacing beats/min) when the CS was paced than when pacing was performed from the HRA. Moreover, CS stimulation produced smaller increments in the A-H interval than did pacing from HRA. The extrastimulus method of testing was done. In cases 1 and 2 the functional refractory period of the A-H tissues was 15 to 25 msec shorter during CS pacing than when pacing from the HRA. In case 3, the low right atrium (LRA) as well as the other two sites were paced. A type 1 gap was seen from HRA, a type 2 gap from CS, and both types appeared when the LRA was paced. Case 4, in which the mid-right atrium (MRA) was also stimulated, had a double pathway from HRA and CS with conduction through the accessory pathway late in the cycle and through the A-V node earlier in the cycle. However, the A-V node could not be penetrated during MRA stimulation. It appeared that the pacing site influenced the A-H conduction pattern and refractoriness, possibly by changing the site and/or mode of entry of the stimulus into the pathways that are responsible for this syndrome.
Body position, electrode level, and respiration effects on the Frank lead electrocardiogram.
Authors: Riekkinen H , Rautaharju P
Published: June 2012

Frank lead ECG/VCG changes with deep inspiration, expiration, and body position were investigated in 194 patients, 100 with an old myocardial infarction and the remaining 94 chosen as a representative sample of catheterization laboratory patients with a variety of cardiac conditions. In a subgroup of 144 of the patients, Frank lead records were made both at the fifth and the fourth intercostal space. Diagnostic interpretation was performed using the VA-Pipberger ECG Program. The results indicate that, in general, body position and electrode level influence on mean intervals and orientation angles is negligible. There was a highly significant decrease in the R and Q wave amplitudes in leads X and Z and in the maximum spatial magnitude of QRS when electrodes were shifted from the fifth to the fourth interspace. The most pronounced decrease in ECG/VCG amplitudes took place in deep inspiration while mean orientation angles changed little, with the exception of QRS elevation. However, while mean changes with body position and electrode level were rather small, substantial orientation and magnitude changes took place in many patients. Diagnostic interpretation of the records changed in 12.5% with electrode level change, in 11.9% with the transition of body position, and in 16.8% with deep inspiration. Strict standardization of electrode positions and recording procedure is suggested, particularly when serial comparison of Frank lead records is planned.
Subendocardial origin of ventricular arrhythmias in 24-hour-old experimental myocardial infarction.
Authors: Horowitz L N , Spear J F , Moore E N
Published: June 2012

In 12 anesthetized open-chest dogs, ventricular epicardial activation maps were constructed and electrograms were recorded from the bundle of His, left bundle branch, and subendocardial Purkinje fibers 24 hours following Harris 2-stage ligation of the left anterior descending coronary artery. All animals developed ectopic ventricular depolarizations and/or ventricular tachycardia. The earliest area of epicardial activation was located along the border of the infarct in the left ventricle in all animals. Bipolar recording from various levels of the conduction system and ventricular myocardium revealed that the earliest recorded electrical activity originated in subendocardial Purkinje fibers which had survived the acute myocardial infarction. The origin of these arrhythmias was further studied by pacing through the electrode which had recorded the early Purkinje activity and comparing the surface ECG and activation sequence with that of the spontaneous rhythm. These data tend to support the hypothesis that ventricular arrhythmias occurring 24-72 hours following acute myocardial infarction have their origin in the subendocardial Purkinje network which has survived the infarction.
Visualization of Ebstein's anomaly of the tricuspid valve by two-dimensional and standard echocardiography.
Authors: Matsumoto M , Matsuo H , Nagata S , Hamanaka Y , Fujita T
Published: June 2012

Seven patients with Ebstein's anomaly were studied by two-dimensional echocardiography, with and without stop-action technique, and by standard echocardiography. Sagittal two-dimensional echocardiograms visualized a small functional right ventricle and a large atrialized right ventricle. These two parts of the chamber were separated by the anterior tricuspid leaflet and its chordae tendineae. The echocardiograms corresponded to the findings of the right ventriculogram. In horizontal two-dimensional echocardiograms a huge anterior tricuspid leaflet, atrialized right ventricle, and a displaced septal tricuspid leaflet, intervening between the functional right ventricle and the sinus portion of the functional right ventricle, were visualized. The origin of the septal tricuspid leaflet was clearly shown to be abnormal in five cases. The left ventricle was small with distinct clockwise rotation of the interventricular septum. Two-dimensional echocardiography provided information useful in evaluation of the functions of the right ventricle and the tricuspid valve and determination of what surgical procedure to follow.
Echocardiographic assessment of bicuspid aortic valves. Angiographic and pathological correlates.
Authors: Radford D J , Bloom K R , Izukawa T , Moes C A , Rowe R D
Published: June 2012

Aortic root echocardiograms were recorded from 89 patients whose aortic valves had also been adequately defined by selective angiography or viewed surgically or at autopsy. The eccentricity index (E.I.) of the aortic leaflets was measured at the onset of diastole and an E.I. of 1.3 or greater was taken as abnormal. Of 31 patients with isolated nonobstruced or mildly obstructed bicuspid aortic valves (7 viewed previously at valvotomy and 24 diagnosed radiologically) 23 (74%) had an abnormal E.I. Varying eccentricity occurred in some of these patients. Central leaflet echoes (E.I. of 1.0 to 1.25) were present in the other eight patients. All 14 patients with nonobstructed tricuspid aortic valves had central echoes. Additional multilayered diastolic echoes were found in patients with bicuspid aortic valves as well as in two patients with abnormal tricuspid aortic valves. The valves of 13 patients with aortic stenosis or incompetence were viewed surgically and the E.I. was abnormal in all patients with a bicuspid aortic valve in this group. Aortic leaflet echo findings were not diagnostically helpful in ten patients with tetralogy of Fallot, one of whom had a normal E.I. with a surgically confirmed bicuspid aortic valve. Of 21 patients with VSD only one had a bicuspid aortic valve but six had an abnormal E.I. This false positive sign was related to a high membranous VSD, sometimes with aortic valve prolapse. It is concluded that an E.I. of greater than or equal to 1.3 in the absence of an associated VSD is diagnostic of a bicuspid aortic valve and can be expected to be found in approximately three-quarters of subjects with this abnormality.