bluuebunny/crossref_metadata_2025 huggingface dataset:
Right ventricular performance in patients with coronary artery disease.
Authors: Ferlinz J , Gorlin R , Cohn P F , Herman M V
Published: June 2012

While left ventricular (LV) performance in patients with coronary artery disease (CAD) has been extensively investigated, little attention has been given to right ventricular (RV) function in this disease. For this purpose, a new geometric model for RV volume has been developed and RV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), stroke volume index (SVI) and ejection fraction (EF) have been determined from biplane RV cineangiograms in 26 patients. Eight patients served as normal (control) subjects (group I). Eighteen patients with obstructive CAD comprised two other groups: six who had no significant disease of the right coronary artery (RCA) (group II) and 12 who had a high grade RCA lesion (group III). The mean values for EDVI, SVI and EF in group I were 76 +/- 11 ml/m2, 50 +/- 6 ml/m2, and 66 +/- 6%. The only significant difference between groups I and II was that SVI was lower in group II than in group I (P less than 0.01). No measurements in groups II and III were statistically different from each other. However, markedly subnormal values were found in group III (EDVI: 61 +/- 16 ml/m2, SVI: 33 +/- ml/m2 and ef: 52 +/- 7%); all values being significantly lower (SVI and EF: P less than 0.001; EDVI: P less than 0.05) than in group I. RV end-diastolic pressure was normal in all patients. These findings may related to 1) reduced RV compliance, 2) distorted LV geometry, 31 possible RV ischemia or 4) reduced Frank-Starling effect.
Five year follow-up of double Master's test, maximal treadmill stress test, and resting and postexercise apexcardiogram in asymptomatic persons.
Authors: Aronow W S , Cassidy J
Published: June 2012

The double Master's test, the maximal treadmill stress test, the resting apexcardiogram, and the postexercise apexcardiogram significantly correlated with the development of subsequent coronary heart disease within five years in 100 asymptomatic persons. The maximal treadmill stress test correlated better than the double Master's test in predicting subsequent coronary heart disease. The presence of both an abnormal maximal treadmill stress and an abnormal a-wave ratio in the postexercise apexcardiogram had the best value in predicting subsequent coronary heart disease.
Relationship between echocardiography, cardiac output, and abnormally contracting segments in patients with ischemic heart disease.
Authors: Sweet R L , Moraski R E , Russell R O , Rackley C E
Published: June 2012

Twenty-four patients with proven coronary artery disease and abnormally-contracting segments were studied by both echocardiography and biplane angiographic techniques. Comparison was made between the left ventricular biplane angiographic volumes and those obtained from echocardiographic measurements which were calculated from cubed function and regression equaltion methods. The percent abnormally contracting segment (ACS) was obtained from biplane left ventricular angiography and was calculated from the diastolic and systolic anteroposterior and lateral angiocardiograms. The angiographic end-diastolic volume correlated with that calculated from the echocardiographic dimensions with an r value of 0.865 and SEE of +/- 22.64 ml. The angiographic end-systolic volume and echo end-systolic volume did not correlate as well, with an r = 0.7063. The difference in stroke volume predicted by the diastolic and systolic echocardiographic dimensions and the actual stroke volume determined by Fick technique was related to the percent abnormally contracting segment of the left ventricle (r = 0.8967). The percent ACS could be estimated from echo and Fick stroke volume measurements by the cube function and regression equations. Echo ventricular volume determinations were analyzed for the cube function method and the regression equations of Fortuin et al. and Teichholz and coworkers, with the method of Fortuin et al. producing the most sensitive relationship: % ACS = 0.32 (SVecho - SVFick) % + 8.9%. The correlation coefficient for the estimate was 0.8967 with a SEE of +/- 4.78%. In patients with coronary artery disease and abnormally contracting segments, echocardiography can provide reliable measurements of left ventricular end-diastolic volume but estimates of end-systolic volume are less accurate. If mitral regurgitation or a ventricular aneurysm can be excluded, the difference in echocardiographic and forward stroke volume by an independent method is related to the angiographic and forward stroke volume by an independent method is related to the angiographic abnormally contracting segment, and this relationship permits estimation of the size of the abnormally, contracting segment.
The variable echocardiographic features in aortic valve endocarditis.
Authors: Wray T M
Published: June 2012

The echocardiographic abnormalities in five cases of aortic valve endocarditis are described and are correlated with the anatomical appearance of the valve at the time of aortic valve replacement. These electrocardiographic findings are compared with those which have been reported previously in this condition. Thickening of the aortic leaflets in systole or multiple linear or coalescent aortic valve echoes in diastole are highly suggestive of valvular vegetations. Ruptured aortic leaflets may produce chaotic, high-frequency echo patterns which differ from those produced by vegetations. The specificity of these echocardiographic patterns is discussed.
A reassessment of the echocardiogram in mitral stenosis.
Authors: Cope G D , Kisslo J A , Johnson M L , Behar V S
Published: June 2012

Echocardiographic and cardiac catheterization findings were compared in 61 patients with mitral stenosis without other significant lesions in an attempt to determine the clinical usefulness of echocardiography in the assessment of such patients. There was a poor correlation between the E-F slope on the echocardiogram and the calculated mitral valve area (r = 0.51). A review of reported data relating the E-F slope to mitral valve area indicated that echocardiographic assessment of mitral valve area had low sensitivity and specificity. The amplitude of excursion of the anterior leaflet did not differ significantly in patients undergoing valvotomy and those undergoind valve replacement. The data obtained suggest that while the echocardiogram is a reliable method of diagnosing mitral stenosis, the E-F slope is an unreliable index of the severity of the lesion.
Identification of congenital malformations of the great arteries in infants by real-time two-dimensional echocardiography.
Authors: Maron B J , Henry W L , Griffith J M , Freedom R M , Kelly D T , Epstein S E
Published: June 2012

Real-time, two dimensional echocardiography was used to identify great artery relations in 23 infants and small children, including 16 patients with angiography documented transposition of the great arteries, tetralogy of Fallot, or pulmonary aresia. Using this technique, the heart was scanned perpendicular to its long axis at the origin of the great arteries. Great arteries cross-sectioned perpendicular to their long axes appear as circles; when sectioned longitudinally these arteries appeared as elongated sausage-shaped structures. I- patients with normally related great arteries, a curcular structure (aorta) always was positioned posterior to an elongated, sausage-shaped structure (distal right ventricular outflow tract and proximal main pulmonary artery). In transposition of the great arteries, two adjacent circular structures were observed; the anterior circle (aorta) was located to the right, left or directly anterior to the posterior circle (pulmonary artery). In pulmonary atresia or hypoplasis, a large posterior circle (aorta) was associated with an anteriorly positioned structure that was either short and small (atretic right ventricular outflow tract) or elongated with an area of severe narrowing (hypoplastic right ventricular outflow tract). Thus, real-time two-dimensional echocardiography provides a rapid, noninvasive means of accurately identifying congenital malformations of the great arteries in infants and small children and may be a useful adjunct to cardiac catheterization in the diagnosis of cyanotic congenital heart disease.
Abnormalities of right ventricular function following Mustard's operation for transposition of the great arteries.
Authors: Graham T P , Atwood G F , Boucek R J , Boerth R C , Bender H W
Published: June 2012

Postoperative data were obtained at cardiac catheterization in twelve patients studied 6-29 months following Mustard's operation for transposition of the great arteries (TGA) to assess the incidence and severity of abnormalities of right ventricular (RV) function. Age at operation was 5-13 months in seven patients (infant group) and 19-25 months in the remaining five patients. RV end-diastolic volume (EDV) decreased in all patients following surgery and averaged 123% of normal in the postoperative group (NS). RV ejection fraction (EF) was depressed postoperatively averaging 0.45 (69% of normal (P less than 0.001) as was RV systolic output (78% of normal, P less than 0.01). LVEDV averaged 65% of normal (P less than 0.001), LVEF 0.67 (103% of normal, NS), and LV systolic output 67% of normal (P less than 0.001) following operation. Left atrial (systemic venous) volume was decreased in all postoperative patients averaging only 39% of normal (P less than 0.001). A high incidence (greater than 50%) of partial baffle obstruction was found and LV systolic output showed a significant negative correlation with baffle gradients. The low output postoperatively may be related to decreased LV filling pressure, a small LV reservoir, and thus a small atrial "booster pump." Pressure-velocity indices of RV contractile function in four patients showed a poor correlation with pump function. Long-term follow-up will be required to determine the clinical significance of the abnormalities of venous return and ventricular function.
Echocardiographic evaluation of pericardial effusion in myxedema. Incidence and biochemical and clinical correlations.
Authors: Kerber R E , Sherman B
Published: June 2012

Pericardial effusion is a recognized consequences of myxedema. Its incidence is unknown, primarily because of past difficulties in establishing the diagnosis. We studied 33 hypothyroid patients by echocardiography. Ten of the 33 patients (30%) had positive echoes for pericardial effusion. Seven of these ten patients had enlarged hearts on chest X-ray. Five patients had cardiac enlargement but no echo evidence of pericardial effusion. Serum concentrations of thyroxine, 1.8+/-0.3 vs 1.5+/-0.1 mcg/dl and of thyroid stimulating hormone, 34+/-4 vs 38+/-5 muU/ml did not differ in the groups with and without pericardial effusion, respectively. However, the pericardial effusion group had significantly slower heart rates on ECG than those without pericardial effusion: 53+/-8 vs 68+/-2 beats/min, P less than 0.05. Low voltage was present in five of the ten patients with pericardial effusion and five of the 23 nonpericardial effusion patients. None of the patients with pericardial effusion developed tamponade. Seven patients with pericardial effusion were restudied after periods of thyroxine replacement therapy ranging from six months to two years. All were euthyroid and had negative echoes on follow-up, but two still showed cardiomegaly on chest X-ray (both had associated coronary artery disease). We conclude that pericardial effusion occurs frequently in patients with myxedema. Tamponade is uncommon and the effusions disappear with thyroid replacement therapy. Cardiomegaly on chest X-ray and low voltage on ECG are not reliable indicators of pericardial effusion.
Double-outlet right ventricle associated with persistent common atriventricular canal.
Authors: Sridaromont S , Feldt R H , Ritter D G , Davis G D , McGoon D C , Edwards J E
Published: June 2012

A variant of double-outlet right ventricle (DORV) associated with common atrioventricular (A-V) canal was identified. As yet, this syndrome has not been successfully repaired. Of 16 patients with this diagnosis, 14 had the diagnosis confirmed at postmortem examination and two had the diagnosis confirmed by exploratory cardiotomy. The 16 patients were divided into two groups according to the position of the cardiac apex: group 1, ten patients with levocardia, and group 2, six patients with dextrocardia and ventricular inverson. When pulmonary stenosis was present, the clinical presentation was similar to that in tetralogy of Fallot, and when such stenosis was not, the presentation was similar to that in ventricular septal defect with bidirectional shunting. The electrocardiogram had the typical feature of common A-V canal. The right ventricular angiocardiogram had features typical of DORV. The left ventricular angiocardiogram revealed left ventricular outflow deformity typical of A-V canal in patients with levocardia but not in those with dextrocardia. Splenic anomalies were commonly seen (nine of the 16 patients). Asplenia was present in seven, and polysplenia in two. Ten patients had persistent left superior vena cava, seven had common atricum, six had anomalous pulmonary venous connection, and three had subaortic stenosis. Twelve of the 16 patients had pulmonary stenosis. Of the 16, 14 had common A-V canal (Rastelli type C) and two had a ventricular septal defect of the persistent common A-V type.
Coarctation of the aorta associated with aortic valvular atresia.
Authors: Von Rueden T J , Knight L , Moller J H , Ewards J E
Published: June 2012

The aortas in 41 specimeans of aortic atresia (ten with associated mitral atresia) were studied for the presence of coarctation of the aorta. The basic lesion, causing varying degrees of obstruction, was observed in 31 instances (75%), 24 minor, seven with major degrees of obstruction. In half, the aortic lesion lay proximal to the ductus, and in the majority of the remainder, opposite the ductus arteriosus. The location of lesion and degree of obstruction was essentially the same whether aortic atresia occurred alone or in association with mitral atresia. Angiography is a fairly reliable method of identifying coarctation associated with aortic atresia. An additional point of interest was that in aortic atresia alone there was strong dominance of the male sex, while this tendency was not observed when mitral atresia was associated with aortic atresia.
Studies on magnesium's mechanism of action in digitalis-induced arrhythmias.
Authors: Specter M J , Schweizer E , Goldman R H
Published: June 2012

The mechanism by which magnesium affects digitalis-induced arrhythmias was studied in dogs with and without beta-receptor blockade. Digoxin was infused at a rate of 2.5mug/kg/min until ventricular tachycardia developed, then half the animals were given MgSO4, the other half saline. In animals given MgSO4, sinus rhythm was immediately re-established; in animals given saline, ventricular tachycardia persisted. In animals with beta-receptor blockade, MgSO4 was as effective in abolishing ventricular tachycardia as in those without beta-receptor blockade. We found no evidence that magnesium re-activated digoxin-inhibited (Na+, K+)-ATPase, altered myocardial or microsomal digoxin binding, or acted via the autonomic nervous system. Magnesium's direct effect on calcium and potassium fluxes across the myocardial cell membrane may be the mechanism of its antiarrhythmic action in digitalis-toxic arrhythmias.
Time dependent changes in the functional properties of the atrioventricular conduction system in man.
Authors: Reddy C P , Damato A N , Akhtar M , Ogunkelu J B , Caracta A R , Ruskin J N , Lau S H
Published: June 2012

Time dependent changes in the electrophysiological properties of the atrioventricular conducting system (AVCS) were determined at two or more cycle lengths (CL) in 22 patients using bundle of His (H) electrograms, incremental atrial pacing and atrial extrastimulus method. The atrioventricular (A-H interval) and intraventricular (H-V interval) conduction times and refractory periods (RP) of the atrium, the A-V node (AVN) and His-Purkinje system (HPS) were measured during the control period, and repeat measurements were made after a 30 minute interval in eight patients (group A), after a 60 minute interval in nine (group B) and after 30 and 60 minute intervals in five (group C). No statistically significant changes from control values were seen after 30 and 60 minute intervals in any group in sinus rate, A-V nodal conduction time and the onset of A-V nodal Wenckebach block. H-V intervals were identical to the control values in all groups. Insignificant changes from control values occurred in RP of the atrium and HPS. Only the functional refractory period (FRP) of the AVN showed a statistically significant decrease from control values in groups B and C. This decrease could be explained by changes in autonomic tone. These observations in general confirm the reproducibility of electrophysiological properties of AVCS within one hour, and further support the validity of the techniques utilized in this and previously reported studies in the evaluation of cardioactive drugs.
Significance of new Q waves after aortocoronary bypass surgery. Correlation with changes in ventricular wall motion.
Authors: Sternberg L , Wisneski J A , Ullyot D J , Gertz E W
Published: June 2012

From June 1969 to December 1974, 142 patients underwent aortocoronary bypass surgery at the Veterans Administration Hospital, San Francisco. Seventeen patients developed new Q waves; two of four deaths in the hospital occurred among these 17 patients. Preoperative and postoperative catheterization data were available for analysis in 12 of the 15 surviving patients. Longitudinal, transverse, and hemiaxial segmental analysis of preoperative and postoperative single plane, 30 degrees right anterior oblique left ventriculograms revealed deterioration in wall motion in all 12 patients. The deterioration corresponded to the area on the electrocardiogram where the new Q waves appeared. In ten of 12 patients, ejection fraction also deteriorated. Twenty-six of 29 grafts were patent. New Q waves after aortocoronary bypass surgery correlate well with the appearance of localized abnormalities in wall motion. We found no evidence that perioperative appearance of Q waves was not due to new perioperative myocardial infarction.
Coronary occlusion during coronary angiography.
Authors: Guss S B , Zir L M , Garrison H B , Daggett W M , Block P C , Dinsmore R E
Published: June 2012

Between January 1, 1970, and December 31, 1974, 2981 patients underwent coronary arteriography. Twelve acute coronary dissections or embolizations occurred, an incidence of 0.4%. The incidences of acute occlusions for the Sones and Judkins techniques were 0.19% (4/2077 studies) and 0.88% (8/940), respectively. No instance of acute occlusion has occurred during the past 490 studies performed by the Judkins technique. Eight patients with right coronary artery dissections or circumflex emboli were treated medically. All survived, but in seven a myocardial infarction evolved. Four patients underwent emergency saphenous venous bypass grafting because of refractory ventricular fibrillation (two patients) or because large amounts of myocardium were thought jeopardized (two patients). All patients in this group had interruption of flow supplying the left anterior descending coronary artery. Despite surgical intervention in less than three hours in all patients, survivors all sustained transmural myocardial infarctions. Three patients survived surgery and were discharged home.
Myocardial metabolic studies in prolapsing mitral leaflet syndrome.
Authors: Natarajan G , Nakhjavan F K , Kahn D , Yazdanfar S , Sahibzada W , Khawaja F , Goldberg H
Published: June 2012

Patients with prolapsing mitral leaflet syndrome (PML) frequently have chest pain of undetermined etiology. Twenty-three patients with PML underwent cardiac hemodynamic, angiographic, and metabolic studies. The latter were performed during control spontaneous heart rate and tachycardia by right atrial pacing. Myocardial supply-demand ratio (DPTI:SPTI) was estimated from the planimetric integration of the diastolic area (diastolic pressure time index = DPTI) and systolic area (systolic pressure time index = SPTI) of the central aortic pressure. Chest pain during pacing occurred in five patients. In two patients, it was associated with ST depression typical of ischemia on the electrocardiogram. Myocardial lactate abnormalities (lactate production or less than 10% extraction) occurred in seven patients during pacing tachycardia and was present in two patients during control state. DPTI:SPTI ratio during control state was 1.22 (+/- 0.07 SE) and decreased to 0.85 (+/- 0.05 SE) during pacing tachycardia. It is concluded that the myocardial lactate abnormalities in PML, which were present in approximately 30% of the patients in the present series, are most likely due to myocardial hypoxia. Whether or not the hypoxia is secondary to "small vessel disease" is not elucidated by this study.
Vasodilator therapy in acute myocardial infarction. A comparison of sodium nitroprusside and nitroglycerin.
Authors: Armstrong P W , Walker D C , Burton J R , Parker J O
Published: June 2012

Twenty-six patients with complicated acute myocardial infarction were studied in order to compare the hemodynamic effects of sodium nitroprusside (NP) and nitroglycerin (GTN). All patients received NP and 18 of the 26 also received GTN to evaluate both drugs in the same individuals. Both agents produced significant declines in mean arterial pressure, total peripheral resistance (TPR), and heart rate systolic blood pressure product. However, in the 18 patients who received both drugs GTN produced a greater fall (P less than 0.05) in pulmonary capillary wedge pressure (PCW) (25 to 15 mm Hg) than did NP (24 to 17 mm Hg) and a greater increment (P less than 0.01) in (see article) (0.98 to 1.43) than NP (0.98 to 1.16). These data confirm the potent vasodilatory effects of NP and GTN and suggest that NP has a relatively balanced effect on the arterial and venous circulation, and GTN seems to produce more potent venodilatation than arterial dilatation. These observations provide a basis for a more rational choice of vasodilator agents based on initial hemodynamic measurements in complicated acute myocardial infarction.
Plasma and atrial propranolol after preoperative withdrawal.
Authors: Romagnoli A , Keats A S
Published: June 2012

Of 34 patients scheduled for aortocoronary bypass operations who were withdrawn from chronic propranolol therapy between 18 and 48 hours before anesthesia and operation, propranolol was detected in the plasma of nine and in atrial tissue of five patients. Higher plasma levels were associated with higher propranolol intake and with shorter time of withdrawal. In 15 patients withdrawn preoperatively from propranolol the heart rate and blood pressure response to 3 mug isoproterenol was not significantly different from the response of similar patients who had received no propranolol. In contrast to the response of healthy subjects, most patients with coronary artery disease responded to isoproterenol with a decrease in systolic blood pressure. Plasma propranolol levels after a 0.5 mg bolus given intravenously during operation produced a peak level of 40 ng/ml in one minute and disappeared in five minutes. These studies suggest that no beta blockade persists 18 hours after acute preoperative withdrawal of propranolol in patients taking up to 300 mg per day for control of angina. In view of the reported hazards of abrupt withdrawal of propranolol before operation and the reported usefulness of propranolol in treating tachyarrhythmias during operation, we suggest that early preoperative withdrawal of propranolol may be more hazardous than its continuation before coronary bypass operations.
Postmortem tissue digoxin concentrations in infants and children.
Authors: Kim P W , Krasula R W , Soyka L F , Hastreiter A R
Published: June 2012

The concentrations of digoxin in tissues of premature infants, full-term infants and older children obtained at autopsy were determined by a radioimmunoassay procedure. Infants were found to have much higher concentrations in the right and left ventricle (about 190 ng/g) than older children (about 70 ng/g) and adults as reported in the literature. Renal concentrations were lower in the premature group which may be related to their limited excretory capacity for digoxin. The relatively high myocardial concentrations of digoxin found in this study suggest that the usually recommended doses for infants may be excessive.
Observer agreement in evaluating coronary angiograms.
Authors: Detre K M , Wright E , Murphy M L , Takaro T
Published: June 2012

The reliability of interpretation of coronary arteriography as a diagnostic tool was investigated in a sub-study of the VA Cooperative Study of Surgical Treatment for Coronary Arterial Occlusive Disease. Twenty-two physicians with varying levels of experience read 13 cine angiograms -- blind -- on two different occasions. Analysis of inter- and intraobserver variability showed that angiographic items about which observers were most inconsistent from one reading to the other had the largest interobserver disagreement as well. They were the distal portions of the left anterior descending and left circumflex arteries. Among the items on which there was most consistent agreement -- namely, the right main coronary artery and presence of ventricular aneurysm -- there was most often agreement between observers as well. When individual readers were evaluated, some observers were far more consistent in their own readings of all the angiographic items than others. This intraobserver agreement in turn correlated fairly well with how often they agreed with the other observers and with how much experience they reported having in reading coronary cineangiograms.
Left ventricular function in tricuspid atresia. Angiographic analysis in 28 patients.
Authors: La Corte M A , Dick M , Scheer G , La Farge C G , Fyler D C
Published: June 2012

Thirty-one left ventricular (LV) biplane angiograms were performed in 28 patients with tricuspid atresia. Measurements of left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume were obtained by the modified Simpson's rule and systolic ejection fraction (EF) calculated. Left ventricular volumes and ejection fractions were also obtained in 19 control patients with no significant heart disease. The patients with tricuspid atresia were classified according to the appearance of the pulmonary vascularity on initial radiologic examination: Group A, decreased pulmonary vascularity; Group B, increased pulmonary vascularity. In the 13 group A infants who were unoperated, LVEDV was increased and EF mildly diminished. In the group B patients LVEDV was increased and EF normal. In the 12 group A patients with surgical shunts LVEDV was elevated. The five group A patients with long-standing systemic artery to pulmonary artery anastomoses (greater than 10 years) showed the largest LVEDV and the poorest EF. The angiographic data indicate that patients with tricuspid atresia experience significant LV dysfunction as a consequence of longstanding LV volume overload. The early detection of LV dysfunction may be an indication for a right ventricular bypass procedure in these patients.
Clinical, angiographic, and hemodynamic findings in patients with anomalous origin of the coronary arteries.
Authors: Chaitman B R , Lespérance J , Saltiel J , Bourassa M G
Published: June 2012

Clinical and angiographic features of 31 patients with anomalous coronpary artery origin are reviewed. Of 17 aberrant circumflex arteries from the right sinus of Valsalva or artery, each was retro-aortic, six atherosclerotic, and seven irrigated a small area of myocardium. Of seven anomalous right coronary arteries from the left sinus of Valsalva or artery, each was ante-aortic and two atherosclerotic. Aberrant origin of the circumflex or right coronary artery was a benign anomaly. The proximal course of seven aberrant left coronary arteries from the right sinus of Valsalva or right coronary artery was related to clinical events. The anomaly was best demonstrated in the lateral view. In five cases, coronary blood flow during exercise and myocardial metabolism during pacing were assessed. Two had had a previous infarction with nonatherosclerotic arteries. Exercise coronary blood flow was normal in four and low in one patient. Pacing resulted in lactate production in two with atherosclerotic and one without atherosclerotic arteries. We conclude that anomalous left coronpary origin from the right sinus of Valsalva can result in significant myocardial ischemia and infarction.
Aneurysm of the membranous ventricular septum in transposition of the great arteries.
Authors: Vidne B A , Subramanian S , Wagner H R
Published: June 2012

In patients with transposition of the great arteries (TGA), both the D- and L- forms, an aneurysm of the membranous ventricular septum (AMS) produces subpulmonic stenosis due to the higher right ventricular pressure which forces the aneurysm to protrude into the left ventricular, i.e., subpulmonic, outflow tract. The clinical signs and symptoms, hemodynamic findings as well as surgical results were analyzed in eight patients with TGA and AMS. The presence of an AMS should be suspected from hemodynamic data consisting of a combination of elevated left ventricular pressure, gradient across the left ventricular outflow tract and presence of a small ventricular septal defect with or without pulmonary artery hypertension. The AMS can be demonstrated by a right ventricular injection in the lateral view. The anomaly needs to be corrected at the time of the Mustard procedure. If uncorrected it may lead to postoperative death or progressive obstruction. In the presence of an aneurysm even small ventricular septal defects should be closed by a patch and the aneurysm should be excised.
Successful resuscitation of two near simultaneous cases of cardiac arrest with a review of fifteen cases occurring during supervised exercise.
Authors: Mead W F , Pyfer H R , Thrombold J C , Frederick R C
Published: June 2012

Two men with coronary heart disease experienced cardiac arrests during a recent exercise rehabilitation session. Fifteen cases of ventricular fibrillation have occurred in this program since 1968, making an average of one per six-thousand man hours of supervised exercise training. All were successfully resuscitated with no sequelae. Analysis of the patients who experience ventricular fibrillation suggests that treating patients with exercise-induced premature ventricular contractions with anti-arrhythmic drugs, proper attention to serum potassium levels, strict adherence to training pulse rates, and proper warm-up might help to prevent future similar events in an exercise program. Due to the unpredictability of ventricular fibrillation it seems preferable that individuals who have known coronary heart disease participate in exercise training under proper supervision with appropriate emergency equipment available.
The asymmetrically hypertrophied septum. Further differentiation of its causes.
Authors: Larter W E , Allen H D , Sahn D J , Goldberg S J
Published: June 2012

Fifty-eight subjects with echocardiographic criteria for an abnormal septal to left ventricular posterior wall ratio were studied. Echocardiographic findings were related to clinical cardiac status. Abnormal ratios were found in normal children and in children with a variety of cardiac lesions, only one of which was obstructive or non-obstructive cardiomyopathy. In those without cardiomyopathy, the abnormal ratio usually resolved by one or two years of age. Persistence of abnormal ratio usually occurred in patients with increased right ventricular anterior wall thickness or idiopathic hypertrophic subaortic stenosis. The cause of abnormal ratio is multifactorial.
An unusual form of the transposition complex. Uncorrected levo-transposition with horizontal ventricular septum: Report of two cases.
Authors: Guthaner D , Higgins C B , Silverman J F , Hayden W G , Wexler L
Published: June 2012

A distinctive angiographic appearance is described in two patients who had uncorrected levo-transposition of the great vessels. Although levo-transposition with inversion of the ventricles usually results in physiologically corrected transposition, in these patients the anatomy was arranged in such a way as to result in an uncorrected transposition. The following elements were responsible for this physiological condition: normal atrial situs, inverted ventricles with "criss-cross" atrioventricular flow, levo-transposed great arteries. In addition, the morphological right ventricle was hypoplastic, left sided and superior to the left ventricle and the ventricular septum was horizontal in position. The two ventricles were connected via a large ventricular septal defect. The importance of accurate, detailed, preoperative angiographic demonstration of the anatomic situation is stressed.
Sinus node function in children. Factors influencing its evaluation.
Authors: Yabek S M , Jarmakani J M , Roberts N K
Published: June 2012

Overdrive atrial stimulation was performed in 20 electrophysiologically normal children at the time of routine diagnostic cardiac catheterization, for the determination of the sinus node recovery time (SNRT). Measurements were made at pacing rates of 120, 150, 180, and 200 beats/min. The absolute recovery times demonstrated wide range of values (420-1280 msec). Expressed as a percent of the resting P-P interval, values at pacing rates of 120 and 150 beats/min were 109-166%, with significantly less overdrive suppression (P less than 0.001) occurring at the two faster pacing rates. Atropine diminished the maximum SNRT in all patients tested. This study reports normal values for the SNRT in children. Factors which influence the SNRT are the resting heart rate, the rate of overdrive, and the autonomic tone. In children, the sinus node recovery time should be expressed in terms of the resting sinus interval.
Prolonged His-Q interval in chronic bifascicular block. Relation to impending complete heart block.
Authors: Vera Z , Mason D T , Fletcher R D , Awan N A , Massumi R A
Published: June 2012

Although prolonged infra-His conduction time in bifascicular block is suspected of denoting trifascicular disease, adquate documentation is lacking concerning the correlation between lengthened His-Q interval (H-Q) and the risk of development of complete heart block (CHB). H-Q in conducted sinus beats in patients with bifascicular block associated with Mobitz II or intermittent CHB represents the approximation of maximal H-Q prolongation prior to onset of trifascicular block. To assess this relationship between prolongation of H-Q and trifascicular block, His bundle electrocardiography (HBE) was performed in 50 patients with chronic bifascicular block exhibiting Mobitz II block or transient CHB. Mobitz II or episodic CHB was shown in all patients: within two days prior to HBE in 45/50 patients; in 39/50 patients during HBE; and following HBE in five patients. In 49/50 patients H-Q was prolonged (greater than 55 msec) and in 47 this interval was substantially lengthened (65 msec or greater). Since marked H-Q prolongation in conducted sinus beats was documented in nearly all patients with bifascicular block associated with intermittent complete trifascicular block, we conclude that a considerably lengthened H-Q interval in bifascicular block is not only a usual prerequisite but strong evidence, for impending complete heart block.
Echocardiographic spectrum of Ebstein's anomaly of the tricuspid valve.
Authors: Farooki Z Q , Henry J G , Green E W
Published: June 2012

Sixteen patients aged between one day to 18 years with Ebstein's malformation of the tricuspid valve were studied with ultrasound. The findings were compared with a group of 74 patients without Ebstein's malformation. Two features were considered specific for Ebstein's malformation: 1) ability to record the anterior tricuspid leaflet (ATL) farther to the left of the left sternal border than in the control group; and 2) abnormally prolonged interval between the "C" points of the tricuspid and the mitral valve echoes (McTcI). All other parameters measured were nonspecific for Ebstein's anomaly of the tricuspid valve. The sail sound was recorded in ten patients with Ebstein's malformation and occurred at the time when the anterior tricuspid leaflet was in the most posterior position. In a patient with congenital heart disease, an McTc interval greater than 0.03 sec and recording of an anterior tricuspid leaflet near the apex of the heart strongly suggest the diagnosis of Ebstein's malformation. These two criteria were not fulfilled in any patient who did not have Ebstein's malformation. Conversely, however, absence of these two features does not rule out Ebstein's anomaly of the tricuspid valve.
Cardiac imaging using a phased array ultrasound system. I. System design.
Authors: vonRamm O T , Thurstone F L
Published: June 2012

A new two-dimensional, real-time, high resolution ultrasound imaging system is described. This system uses a linear array of ultrasound transducers to generate tomographic images of the heart in a circular sector format. Phased array techniques allow rapid steering of the ultrasound beam so that images are produced at the rate of 20 per second, or more, while maintaining a resolution of 2-4 mm throughout the field of view.
Relation between echocardiographically determined left atrial size and atrial fibrillation.
Authors: Henry W L , Morganroth J , Pearlman A S , Clark C E , Redwood D R , Itscoitz S B , Epstein S E
Published: June 2012

In an attempt to define quantitatively the relation between left atrial size and atrial fibrillation, echocardiography was used to study 85 patients with isolated mitral valve disease, 50 patients with isolated aortic valve disease, and 130 patients with asymmetric septal hypertrophy. In all three groups of patients, atrial fibrillation was rare when left atrial dimension was below 44 mm (3 of 117 or 3%) but common when this dimension exceeded 40 mm (80 of 148 or 54%). In addition, when left atrial dimension exceeds 45 mm, cardioversion, while initially successful, is unlikely to produce sinus rhythm that can be maintained at least six months. These data suggest that left atrial size is an important factor in the development of atrial fibrillation and in determining the long term result of cardioversion. The pathophysiologic mechansim most consistent with this is that a chronic hemodynamic burden initially produces left atrial enlargement which in turn predisposes to atrial fibrillation. Only prospective studies will determine definitively whether these observations will be useful in decisions concerning prophylactic anticoagulation and elective cardioversion.
Suppression of ouabain-induced ventricular rhythms with aprindine HCl. A comparison with other antiarrhythmic agents.
Authors: Foster P R , King R M , Nicoll A B , Zipes D P
Published: June 2012

Three groups of dogs were given ouabain (mean 60 mug/kg) until an accelerated ventricular escape (AVE) and repetitive ventricular response (RVR) followed cessation of pacing. In a group of six control dogs, the AVE and RVR were found to occur at stable escape intervals for periods of at least three hours. A second group of dogs received various antiarrhythmic agents in an attempt to suppress the AVE and RVR. Quinidine, diphenylhydration, lidocaine, procainamide, and propranolol, were successful in only 0 to 33% of trials. Potassium canrenoate, 12 mg/kg was unsuccessful in three dogs. Verapamil, by bolus, suppressed RVR in 41% and AVE in 21% of trials. KCl, infused until AVE and RVR were suppressed, was successful when the mean serum potassium rose from 3.8 mEq/L to 7.2 mEq/L. Aprindine, 2.86 mg/kg, suppressed AVE and RVR in 14 of 14 dogs. In the third group of dogs, verapamil was infused continuously and suppressed RVR and AVE at a mean cumulative dose of 2.93 mg/kg. Calcium chloride reversed aprindine and verapamil-induced suppression of RVR and AVE. This study demonstrates that RVR and AVE resist suppression by available antiarrhythmic agents in clinically-used doses. Only aprindine was 100% successful at doses used in man. The ionic pathogenesis of RVR and AVE is unknown, but some data suggest the slow current may play an important role.
Pulmonary perfusion abnormalities and ventilation-perfusion imbalance in children after total repair of tetralogy of Fallot.
Authors: Alderson P O , Boonvisut S , McKnight R C , Hartman A F
Published: June 2012

The pulmonary perfusion of 25 children who had total surgical correction of tetralogy of Fallot was evaluated by radionuclide perfusion scans. In addition, 18 had 133Xe ventilation studies. Eighteen of the children previously had palliative systemic-pulmonary shunts; 14 had aortic-pulmonary shunts (Waterston or Potts-Smith) and four had Blalock-Taussig shunts. Seven children had single stage total corrections. An asymmetric perfusion pattern was found in 13 of 18 children who previously had systemic-pulmonary shunts, including 12 of 14 with previous aortic-pulmonary shunts (P less than 0.05). The most common finding was relative hypoperfusion of the lung which had received the palliative shunt (P less than 0.001). The distribution of ventilation remained relatively symmetric, even when perfusion was markedly abnormal, and this resulted in ventilation-perfusion imbalance in several patients. Asymmetric perfusion was significantly less common in patients who had undergone single stage corrections (P less than 0.05). The findings document the frequent occurrence of residual abnormalities of pulmonary perfusion and ventilation-perfusion imbalance in patients who have palliative aortic-pulmonary shunts prior to total repair, and support the position that single stage correction is preferable to aortic-pulmonary shunting in the surgical management of tetralogy of Fallot.
The role of the renin-angiotensin-aldosterone system in cardiovascular homeostasis in normal human subjects.
Authors: Sancho J , Re R , Burton J , Barger A C , Haber E
Published: June 2012

To examine the role of angiotensin II in the maintenance of blood pressure and the control of aldosterone secretion in man, eight normal subjects were studied on a tilt table in sodium replete and sodium depleted states prior to and subsequent to the intravenous infusion of an angiotensin converting enzyme inhibitor (CEI). In both the sodium replete or sodium depleted state, upright tilting resulted in an increase in heart rate and a narrowing of pulse pressure. None of the sodium replete or depleted subjects fainted. Tilting was accompanied by a rise in plasma renin activity with an associated rise in plasma aldosterone concentration. When converting enzyme inhibitor was administered, which blocked the generation of angiotensin II, sodium replete subjects were able to compensate for an upright tilt, despite the absence of angiotensin II, without significant hemodynamic change when compared to control state. In sodium depleted subjects, after the administration of converting enzyme inhibitor, there was a sharp and significant decrease in systolic and diastolic blood pressure associated with a significant rise in heart rate. All but one sodium depleted subject fainted within seven minutes. Both plasma aldosterone concentration and plasma renin activity rose on tilting in both sodium replete and sodium depleted subjects. After the administration of converting enzyme inhibitor, plasma aldosterone failed to rise in association with a rise in plasma renin activity. In supine subjects, after the administration of converting enzyme inhibitor, plasma renin activity rose but plasma aldosterone concentration fell. In sodium depleted subjects, after the administration of CEI, aldosterone fell to a level significantly lower than that in supine controls and to a level no different from the supine sodium replete subject. These results indicate that angiotensin II is essential for blood pressure maintenance in sodium depleted individuals, that angiotensin II exerts a direct feedback control on renin secretion, and that angiotensin II is the primary stimulus to aldosterone secretion in response to both sodium depletion and to posture.
Mineralocorticoid secretion in essential hypertension with normal and low plasma renin activity.
Authors: Messerli F H , Kuchel O , Nowaczynski W , Seth K , Honda M , Kubo S , Boucher R , Tolis G , Genest J
Published: June 2012

In 19 control subjects, 33 patients with essential hypertension and normal plasma renin activity (PRA) and 11 patients with low PRA, secretory rates of 18-hydroxy-11-deoxy-corticosterone (18-OH DOC), 11-deoxycorticosterone (DOC) and corticosterone were measured. Patients with low PRA were significantly older and had higher arterial pressure and slightly lower plasma potassium levels than patients with normal PRA. Mean 18-OH DOC secretion rate was higher in patients with normal PRA (603 +/- 112 SEM mug/24 hr) than in control subjects (219 +/- 19) and considerably higher (P less than 0.001) in patients with low PRA (1800 +/- 472). DOC and corticosterone secretion rates were within normal limits in most hypertensive patients. Plasma aldosterone was significantly higher in the hypertensive population than in control subjects whereas no significant difference was observed between the low- and normal-renin groups. A significant (P less than 0.01) mutual positive correlation was found between the secretion rates of 18-OH DOC, DOC and corticosterone in patients with low plasma renin activity. In contrast, there was no correlation between the secretion rates of the three mineralocorticoids in control subjects and patients with normal plasma renin activity. These data suggest a biosynthetic variation of the mineralocorticoid pathways in essential hypertension.
Absolute determination of cardiac output in intra-aortic balloon pumped patients using the radial arterial pressure trace.
Authors: Herzlinger G A
Published: June 2012

We describe a new method for the absolute determination of cardiac output in intra-aortic balloon pumped (IABP) patients. The method uses the known pumping volume of the IABP balloon and the radial arterial pressure trace, which is commonly used to monitor IABP patients, to determine the cardiac output. Two pressure excursions denoted by P1-P0 and P2-P0, characterizing IABP balloon deflation, and ventricular ejection, respectively, are extracted from the radial trace. The cardiac output (CO) is then determined by the simple relation: CO = (BV) x (P2-P0)/(P1-P0) x HR where HR is the heart rate, and the value for pumped balloon volume (BV) is corrected for the effect of the pressure in the patient's aorta. Comparison with dye dilution and thermal dilution procedures as carried out on a routine basis in a clinical setting produced a good correlation (r = .928). When fit to a straight line through zero output, the data yielded a constant of proportionality of 0.973 between the above formula and the clinical procedures. The procedure does not disturb the patient in any way, and enables continuous monitoring of cardiac output. This has been implemented using a real-time, miniaturized computer and allows much more information to be obtained than in usual single measurements.