bluuebunny/crossref_metadata_2025 huggingface dataset:
Anatomic causes of pulmonary stenosis in complete transposition.
Authors: Shrivastava S , Tadavarthy S M , Fukuda T , Edwards J E
Published: June 2012

Among 166 specimens with classical complete transposition, pulmonary or subpulmonary stenosis was present in 22 cases. The bases for obstruction were pulmonary valvular stenosis (one case), membranous subpulmonary stenosis (nine cases), anomalous attachment of the mitral valve to the ventricular septum (five cases) and combinations of causes (seven cases). Conditions contributing to combinations of causes included the above, in addition to accessory mitral or pulmonary valvular tissue and herniation of a tricuspid valvular pouch through a related ventricular septal defect. In addition to the 166 cases mentioned, our collection contained six cases of atypical complete transposition characterized by a conus being present in the each ventricel. In three of these six, subpulmonary stenosis was present and caused by a narrow inlet to the left ventricular conus.
A study of comparative blood pressure measures in predicting risk of coronary heart disease.
Authors: Rosenman R H , Sholtz R I , Brand R J
Published: June 2012

The Western Collaborative Group Study is a prospective study of 3,154 employed men, aged 39-59 years. Coronary heart disease (CHD) occurred in 257 subjects during 8.5 years of follow-up. The multiple logistic risk model was used to assess the comparative strength of systolic, diastolic, mean arterial and pulse pressure for the prediction of CHD in two age decades after adjustment for age, serum cholesterol, cigarette smoking, behavior pattern and weight. The risk of CHD was more strongly associated with the systolic than the diastolic pressure. The general practice of assessing the importance of blood pressure based only on the diastolic component should be reassessed.
Echocardiographic assessment of left-to-right shunt volume in children with ventricular septal defect.
Authors: Lewis A B , Takahashi M
Published: June 2012

Echocardiograms were performed in 20 infants and children with isolated ventricular septal defects (VSD) undergoing cardiac catheterization. The magnitude of the left-to-right shunt was expressed as the pulmonary-to-systemic flow ratio (Qp/Os) and was compared to a ratio of the echographic left atrial (LA) diameter to the aortic root (Ao) diameter (LA/Ao). The Qp/Qs was also compared to LA/m2. Thirty-three normal children served as controls. The LA/m2 and Ao/m2 were significantly larger in normal infants under one year of age than in children above one year. The LA/Ao, however, was not influenced by age or size. A strong linear relationship was found between Qp/Qs and the LA/Ao (r = 0.96). The LA/Ao measurement appears to be helpful in the noninvasive assessment of the left-to-right shunt in patients with VSD.
Echocardiography in mechanical alternans. With a note on the findings in discordant alternans within the left ventricle.
Authors: D'Cruz I , Cohen H C , Prabhu R , Glick G
Published: June 2012

We described the echocardiographic manifestations of mechanical alternation of left ventricular (LV) contraction during regular sinus rhythm. Chronic LV dilatation and failure existed in all our four cases. Alternation was observed with respect to the following echocardiographic variables: amplitude and rate of increase of amplitude of systolic excursions of the LV posterior wall and ventricular septum (VS); reciprocal changes in the duration of LV ejection and pre-ejection periods (on the aortic valve echo) such that the total duration of LV electromechanical systole remained constant; reciprocal changes in the duration of RV ejection and pre-ejection periods (on the pulmonic valve echo) such that the total duration of RV electromechanical systole remained constant; systolic anterior excursion of the aortic root as a whole; steepness of the mitral EF slope; septal and LV posterior wall diastolic position; and end-systolic LV diameter. In two patients, discordant alternans of the motion of the LV posterior wall and the VS was observed.
The His-Purkinje electrocardiogram in man: an initial assessment of its uses and limitations.
Authors: Berbari E J , Scherlag B J , El-Sherif N , Befeler B , Aranda J M , Lazzara R
Published: June 2012

A methodology is described for noninvasive recording of the electrical activity generated by the His-Purkinje system of man utilizing filtering, high amplification, and signal averaging. A waveform ranging between 1 and 10mu V was observed during the P-R segment. In many individuals, there was temporal overlap between the terminal P wave and the initial portion of the His-Purkinje waveform. In ten patients with long P-R intervals there was a strong correlation (r greater than 0.95) between the H-V time measured by electrode catheter and the duration of the His-Purkinje waveform. In two patients with atrial fibrillation the resultant His-Purkinje waveform was similar in morphology and duration to those observed in the ten patients. In each group H-V time was determined noninvasively and a waveform associated with electrical activation of the major portions of the His-Purkinje system was obtained.
Electrophysiological studies in patients with chronic recurrent ventricular tachycardia.
Authors: Denes P , Wu D , Dhingra R C , Amat-y-Leon R , Wyndham C , Mautner R K , Rosen K M
Published: June 2012

Seventeen consecutive patients with chronic recurrent ventricular tachycardia (VT) were studied in an attempt to delineate the reproducibility and mechanism of this arrhythmia. Six patients had nonsustained and 11 had sustained VT. The following electrophysiological techniques were utilized in an attempt to reproduce VT: 1) rapid atrial and ventricular pacing (17 pts); 2) atrial extrastimulus technique (17 pts); 3) ventricular extrastimulus technique (17 pts); 4) V1V2V3 stimulation technique (5 pts); 5) ventricular pacing from two or more sites (5 pts). Ventricular tachycardia was induced in six of 11 (54%) patients with sustained VT. However, in four there was only a single induction and only in the remaining two patients could VT be repetitively induced. In the latter two patients ventricular tachycardia was induced with both atrial and ventricular stimulation. Ventricular tachycardia could not be induced in any patient with nonsustained VT, although three had spontaneous episodes of ventricular tachycardia during study. In conclusion, in the present series of patients with chronic recurrent VT, this rhythm could not be reproducibly induced in the majority of patients in the cardiac catheterization laboratory utilizing catheter stimulation techniques.
Two to three years of failure-free testing of a rechargeable pacemaker in experimental complete heart block.
Authors: Hughes H C , Brownlee R R , Tyers G F
Published: June 2012

Six hermetically sealed single cell rechargeable mercury-zinc pacemakers (B.T.) that will run continuously for over 4 years between rechargings have paced dogs with complete heart block for from 2 to 3 years. To maintain full cell capacity (over 1,000 mA hours) requires recharging for from 2-3 min/day to 60 to 80 hr once every 4 years, with any variation between these extremes being acceptable. Six realtime bench tests continue after over 7 years and accelerated tests have simulated a minimum of 50 years continuous pacing. Battery voltage is assessed by direct telemetry, eliminating the risk of patient intrinsic rhythm-pacemaker competition which is present with all current indirect (stimulation rate change) battery assessment techniques. The B.T. is an excellent 4-5 year primary pacemaker, fully rechargeable after several 4 year periods of battery rundown. A clinical test series has been initiated.
Angiocardiography with iridium-191m: an ultrashort-lived radionuclide (T1/2 4.9 sec).
Authors: Treves S , Kulprathipanja S , Hnatowich D J
Published: June 2012

Iridium-191m is a potential tracer for angiocardiography and may be of particular value in the evaluation of heart disease in children. It possesses a short half-life (4.9 sec), suitable photon energy (129 keV) and may be obtained as a generator product by decay of its long lived (15.3 day) parent 191 Os. An 191Os leads to 191mIr generator capable of providing 15 mCi of 191mIr in 1.5 ml of eluant is described. The separation of 191mIr from 191Os is achieved by absorbing 191OsC16-2 on an anion exchange resin. The generator employs an additional resin column which is replaced to prevent 191Os breakthrough to become excessive. By this procedure, the breakthrough may be kept below 0.001% over a period of at least one month and after multiple elutions.
Differences in muscle blood flow in upper and lower extremities of patients after correction of coarctation of the aorta.
Authors: Samánek M , Goetzová J , Fiserová J , Skovránek J
Published: June 2012

Using the method 133Xe clearance we investigated blood flow and calculated vascular resistances simultaneously in the muscles of the upper and lower extremities in 58 patients following successful surgical correction of aortic coarctation carried out at age 11.5 (+/- 2.9) years. The interval from operation to investigation was 11.5 (+/- 4.5) years. Resting and maximal ischemic exercise blood flows in the upper extremity were decreased and the duration of maximal blood flow was shortened. Values recorded from the lower extremities did not differ from normal controls. The difference between upper and lower extremities was statistically significant. Vascular resistance during maximal blood flow was higher in the upper extremities than in the lower. Differences between upper and lower extremities did not change after vasodilation elicited by amyl nitrite. The degree of differences was not dependent upon the age at operation, the age of the patients at investigation, or on the time interval between operation and investigation.
Cardioversion and "false positive" technetium-99m stannous pyrophosphate myocardial scintigrams.
Authors: Pugh B R , Buja L M , Parkey R W , Poliner L R , Stokely E M , Bonte F J , Willerson J T
Published: June 2012

The present studies performed in experimental animals demonstrate that electrical direct current cardioversion can produce skeletal muscle damage and increased technetium-99m stannous pyrophosphate (99mTc-PYP) uptake; in experimental animals the electrically damaged skeletal muscle shows necrosis with extensive calcium deposition. In addition, the frequent administration of high energy cardioversion produces myocardial necrosis with calcium deposition, increased 99mTc-PYP myocardial uptake and a positive 99mTc-PYP myocardial scintigram. The data indicate that, if diagnostic 99mTc-PYP myocardial scintigraphy is contemplated after cardioversion, paddle placement should be slightly removed from the anteroposterior projection of the heart on the external chest wall to avoid possible subsequent confusion between increased myocardial and skeletal muscle uptake of 99mTc-PYP. If multiple high energy cardioversion episodes are necessary, myocardial necrosis resulting from electrical injury may occur and be responisble for increased myocardial uptake of 99mTc-PYP with a resultant positive 99mTc-PYP myocardial scintigram.
Analysis of surgically-induced right bundle branch block pattern using intracardiac recording techniques.
Authors: Sung R J , Tamer D M , Garcia O L , Castellanos A , Myerburg R J , Gelband H
Published: June 2012

Using intracardiac recording techniques, His bundle (H) and right ventricular apical (RVA) electrograms were recorded in 16 patients with a postoperative electrocardiographic pattern of right bundle branch block (RBBB). Their ages ranged from 5 to 12 years (mean 6.9 years) at surgery and the follow-up period was 1 to 7 years (mean 2.7 years). All were asymptomatic and in sinus rhythm at the time of study. The P-A interval was normal in all and the A-H, H-V, and V-RVA intervals were prolonged in one, one, and six patients, respectively. The V-RNA interval was normal (less than or equal to 30 msec) in ten out of the 11 patients (91%) without associated left anterior hemiblock (LAH), indicating a physiologically intact main right bundle branch, and was abnormally lengthened (45-62 msec) in all five patients (100%) with associated LAH. These findings suggest that there are two subgroups of patients with surgicall-induced RBBB pattern and the measurement of the V-RVA interval in conjunction with the H-V interval may be of ultimate importance in understanding the long-term prognostic implication of surgically-induced RBBB pattern with or without LAH.
Electrophysiologic effects of propranolol on sinus node function in patients with sinus node dysfunction.
Authors: Strauss H C , Gilbert M , Svenson R H , Miller H C , Wallace A G
Published: June 2012

The electrophysiologic effects of intravenously administered propranolol (0.1 mg/kg) on three parameters of sinus node function were examined in ten symptomatic patients with sinus node dysfunction. The patients ranged in age from 26 to 79 years. Symptoms ranged from fatigue to frank syncope. Sinoatrial (SA) block and sinus pauses were observed in one patient; sinus pauses alone were observed in three patients. Five (5/10) patients had intraatrial block; three (3/10) patients had atrioventricular block; four (4/10) patients had an intraventricular conduction disturbance. At the time of electrophysiologic study, two patients had a control spontaneous sinus cycle length that exceeded 1000 msec. Following propranolol, the mean spontaneous cycle length increased by 17.4% (924 to 1085 msec, P less than 0.005) and spontaneous second degree SA block reappeared in the one patient. The maximum escape cycle ranged from 116% to 229% of the prepacing spontaneous cycle length and was considered to be prolonged in two of ten patients. Propranolol had no significant effect on the maximum escape cycle/prepacing cycle length X 100 (%). The estimated sinoatrial conduction time (SACT) was determined in seven patients and ranged in value from 120 to 238 mes. Propranolol increased the mean value of the estimated SACT from 179 to 213 msec, P less than 0.025. Propranolol may cause marked bradyarrhythmias in some patients with sinus node dysfunction, and should be used with caution in these patients.
Mitral valve area in combined mitral stenosis and regurgitation.
Authors: Askenazi J , Carlson C J , Alpert J S , Dexter L
Published: June 2012

Eight patients with mixed mitral stenosis and regurgitation underwent hemodynamic and angiographic study prior to mitral valve replacement. The stenotic orifice of the mitral valve was calculated employing the total left ventricular stroke volume by cineangiography as the numerator of the Gorlin Formula. Excellent agreement with the measured orifice of the mitral valve was obtained using a value of 37.9 (0.85 X 44.5) for the constant in the Gorlin formula as recommended by Cohen and Gorlin. Recalculation of this constant independently by our data yielded a value that was almost identical. Regurgitant flows and orifice sizes were calculated for each patient using the same constant as for calculation of the stenotic orifices.
Echocardiographic features of congenital left ventricular inflow obstruction.
Authors: LaCorte M , Harada K , Williams R G
Published: June 2012

The echocardiographic features of congenital left ventricular inflow obstruction are described in six patients. The echocardiograms in two patients with cor triatriatum were distinguished by normal mitral valve motion and an abnormal echo within the left atrium. In two patients with supravalvar mitral ring, in addition to abnormal mitral valve motion, an abnormal echo, presumably originating from the obstructive membrane, was located between the anterior and posterior mitral leaflets. In two cases of parachute mitral valve, mitral valve motion was abnormal. In one of these cases there were multiple mitral valve echoes similar to those found in supravalvar mitral ring. The echocardiographic identification of an obstructive membrane within the left atrium is difficult because of the occurrence of artifacts. However, membranes may be identified if careful scanning techniques are employed in patients in whom left ventricular inflow obstruction is suspected. The echocardiogram is useful in detecting mitral valve abnormalities in these patients and is valuable in cases where mitral valve replacement is contemplated.
The protective effect of hyperosmotic mannitol in myocardial ischemia and necrosis.
Authors: Powell W J , DiBona D R , Flores J , Leaf A
Published: June 2012

Morphologic and hemodynamic changes that occur following coronary occlusion are examined. The effectiveness of hyperosmotic mannitol in lessening the extent of myocardial damage is assessed and mechanisms for its action discussed. Forty and 60 min of coronary vascular occlusion followed by 15 and 45 min of reflow were associated with a persistence of ischemia following reflow of blood, as established by infusions of silastic into the aortic root. Electron microscopic studies demonstrated myocardial and endothelial cell swelling at the end of the reflow period. The process of cell swelling appeared to be initiated during the period of arterial occlusion. This cell swelling was reduced by elevation of serum osmolality by 30-40 mOsm above control with the administration of mannitol during and following occlusion. There was an associated 40-50% reduction of vascular resistance following occlusion if mannitol was administered. In addition, the extent of necrosis, which was widespread in untreated hearts 12 hours after occlusion, was strikingly less in the hearts of dogs which received mannitol. Thus, in ischemic myocardium, elevation of osmolality by mannitol reduces myocardial necrosis, probably through its restoration of normal cell volume.
Subpulmonary obstruction in congenitally corrected transposition of the great arteries due to ventricular membranous septal aneurysms.
Authors: Krongrad E , Ellis K , Steeg C N , Bowman F O , Malm J R , Gersony W M
Published: June 2012

The clinical, hemodynamic, and angiographic observations, as well as the surgical approach used for repair in three patients with congenitally corrected transposition of the great arteries and ventricular membranous septal aneurysms, are presented. In two of the three patients the membranous septal aneurysm caused subpulmonary obstruction, with 94 and 125 mm Hg systolic gradients. In each patient the aneurysm was demonstrated by angiocardiography, which also showed differences in size and shape with cardiac systole and diastole. Review of the previously described reports indicates that patients with congenitally corrected transposition often display various forms of pulmonary outflow obstruction and when a ventricular membranous septal aneurysm exists, a significant subpulmonary obstruction is present in most patients. The unique anatomic relationship between the pulmonary artery and a ventricular membranous septal aneurysm in patients with transposition of the great arteries with and without atrioventricular discordance explains why subpulmonary obstruction sometimes develops.
The isovolumic contraction time of the left ventricle. An echographic study.
Authors: Hirschfeld S , Meyer R , Korfhagen J , Kaplan S , Liebman J
Published: June 2012

The echographic isovolumic contraction time (ICT) of the left ventricle (LV) was measured in order to assess alterations of LV performance in children with various forms of cardiac disease. The echographic ICT was defined as the interval between coaptation of the anterior and posterior mitral valve leaflets and aortic cusp opening. Four groups of patients were evaluated: normal (48); LV myocardial disease (20); patent ductus arterosus (PDA) (19); and aortic stenosis (AS) (15). In normal children ICT shortened with decreasing age and increasing heart rate. Isovolumic contraction time was more influenced by heart rate (HR) than age, but the relationship was still weak (r = 0.61). In patients with LV myocardial disease ICT was markedly prolonged, while in children with patent ductus arteriosus and aortic stenosis it was shortened as compared with normal children (P less than 0.01).
Comparison between the effects of nitroprusside and nitroglycerin on ischemic injury during acute myocardial infarction.
Authors: Chiariello M , Gold H K , Leinbach R C , Davis M A , Maroko P R
Published: June 2012

This clinical and experimental investigation was designed to delineate and compare the relative effects of sodium nitroprusside (NP) and nitroglycerin (TNG) on electrocardiographic ischemic injury following acute myocardial infarction in patients and following coronary artery occlusion in dogs. Accordingly, in ten patients with anterior acute myocardial infarction and ST-segment elevation stable for 60 min, the effects of NP (average 95 mug/min i.v.) and TNG (average 0.48 mg sublingually) were studied. The hemodynamic actions of NP and TNG were directionally similar. However, NP increased average ST-segment elevation (ST) by 2.0 +/- 0.2 mm, while TNG reduced ST by 1.4 +/- 0.4 mm. In order to clarify this disparity, coronary artery occlusions were carried out in 14 open-chest dogs. During control, NP and TNG time periods, epicardial electrograms were recorded and regional myocardial blood flow (RMBF) determined by the microsphere technique. Nitropruside increased ST-segment elevation from 4.6 +/- 0.6 to 5.7 +/- 0.6 mV (P less than 0.05) and reduced RMBF from 35 +/- 3 to 27 +/- 2 ml/min/100 g (P less than 0.01) in the ischemic zones. In contrast, TNG reduced ST-segment elevation from 4.9 +/- 0.7 to 3.0 +/- 0.7 mV (P less than 0.05), while increasing RMBF TO 43 +/0 4 ml/min/100 G (P less than 0.05) and the endo/epicardial ratio from 0.57 +/- 0.06 to 0.69 +/- 0.07 (P less than 0.01). Although TNG and NP exhibit similar hemodynamic effects, TNG reduced electrocardiographic ischemic injury, at least in part, by increasing perfusion of the ischemic areas and redistributing it favorably, while NP increased electrocardiographic ischemic injury, at least in part, by reducing perfusion. Therefore, TNG seems preferable to NP for reducing preload and afterload in patients during the early phase of acute myocardial infarction.
Spontaneous resolution of massive congenital tricuspid insufficiency.
Authors: Boucek R J , Graham T P , Morgan J P , Atwood G F , Boerth R C
Published: June 2012

Four cases of congenital tricuspid insufficiency (CTI) are presented in whom spontaneous improvement occured. There was no evidence of Ebstein's disease in three of the four. All presented with similar clinical and laboratory findings including massive cardiomegaly, mild to moderate congestive heart failure, and moderate to severe desaturation. Catheterization data demonstrated severe TI and right-to-left atrial shunting. During the period of follow-up, up to 3.5 years, all symptoms have spontaneously disappeared. Clinical and angiocardiographic evidence for minimal residual TI have remained. Right atrial and right ventricular volume measurements were markedly abnormal initially and returned to normal or near normal. These measurements may be a useful method for quantitating the severity of tricuspid insufficiency. The course of the three infants with massive CTI (without Ebstein's disease) differs from previous reports and may be important both in formulating future management plans and in defining the etiology of the disorder.
The palliative Mustard operation for double outlet right ventricle or transposition of the great arteries associated with ventricular septal defect, pulmonary arterial hypertension, and pulmonary vascular obstructive disease. A report of eight patients.
Authors: Bernhard W F , Dick M , Sloss L J , Castaneda A R , Nadas A S
Published: June 2012

Five patients with double outlet right ventricle, ventricular septal defect, pulmonary arterial hypertension and pulmonary vascular obstructive disease and three patients with complete d-transposition of the great arteries, ventricular septal defect, pulonary arterial hypertension and pulmonary vascular obstructive disease underwent an elective Mustard baffle operation. The ventricular septal defect was not closed. A large patent ductus arteriosus was divided in three patients. Seven of the eight patients are alive five to 32 months after surgery; one patient died 11 months after surgery. Cyanosis, dyspnea on exertion, and exercise limitation improved initially in all and has persisted in the survivors. In pre and postoperative hemodynamic studies in four patients, systemic arterial oxygen saturation and effective pulmonary blood flow increased from mean values of 70% to 90% and 1.7/min/m2 to 3.3 L/mon/m2, respectively. Absolute systemic and pulmonary flows, and pressures and resistances, were not significantly altered. Criteria for selection of patients with transposition of the great arteries of double outlet right ventricle who would benefit from a palliative Mustard procedure (Mustard atrial baffle without closure of the ventricular spetal defect) are: 1) severe symptoms; 2) pulmonary arteiral hypertension (75% systemic) with pulmonary vascular obstructive disease; and 3) pulmonary artieral oxygen saturation greater than systemic (ascending aorta) arterial oxygen saturation by approximately 10%.
Cardiac valvular anomalies in Fabry disease. Clinical, morphologic, and biochemical studies.
Authors: Desnick R J , Blieden L C , Sharp H L , Hofschire P J , Moller J H
Published: June 2012

The cardiovascular abnormalities were investigated in two unrelated hemizygous males with Fabry disease who had clinical mitral insufficiency. Postmortem examination of their hearts revelaed anatomic, ultrastructural and biochemical abnormalities resulting from defective activity of the lysosomal enzyme, alpha-galactosidase A. The ultrastructural and biochemical studies demonstrated the marked accumulation of the major glycosphingolipd substrate, trihexosyl ceramide, in the lyosomes of all the cardiac tissues examined; the greatest concentrations were found in the mitral valve and elft ventricular myocardium. Intriguingly, digalactosyl ceramide, a glycosphingolipid substrate not detectable in normal lung, vessel or cardiac tissues, was found increased only in the lung and right heart tissues. Morphologic and chemical examination of cardiac and systemic vessels demonstrated accumulation of trihexosyl ceramide in lysosomes of the vascular endothelium. These studies demonstrate that the progressive accumulation of trihexosyl ceramide in the lysosomes of the cardiac structures and vascular system leads to the multiple cardiovascular manfiestation of Fabry disease.
Alveolar rhabdomyosarcoma involving the heart. An echocardiographic, angiographic and pathologic study.
Authors: Orsmond G S , Knight L , Dehner L P , Nicoloff D M , Nesbitt M , Bessinger F B
Published: June 2012

A 12-year-old girl, who had had an above-knee amputation of the left leg for a soft tissue sarcoma six years prior to this admission, presented with syncope, angina, and signs of aortic stenosis. Echocardiography demonstrated a mass arising from the interventricular septum with obstruction of the left ventricular outflow tract and aortic valve. Cardiac catheterization and angiography confirmed these findings. At operation, a tumor was found involving the interventricular septum. Histologically, it was an alveolar rhabdomyosarcoma, and it appeared similar to the previous tumor. The patient was treated by partial surgical resection, cytotoxic drugs and localized radiation therapy and has been followed by serial echocardiography.
George C. Griffith lecture. The role of renin in normal and pathological cardiovascular homeostasis.
Authors: Haber E
Published: June 2012

Recently, the availability of a number of specific inhibitors of the renin-angiotensin system has made it possible to address certain critical questions concerning the role of angiotensin II in physiologic homeostasis and in a number of pathologic states. These studies indicate that angiotensin II does not have an obligatory role in blood pressure maintenance in the normal, sodium replete individual, but it is essential following sodium depletion. The role of angiotensin II in feedback control of renin secretion is confirmed as is its importance in aldosterone stimulation both in relation to posture and sodium depletion. Angiotensin II is responsible for the initial pressor response of experimental renovascular hypertension and appears to be important in the initiation of chronic renovascular hypertension. Converting enzyme blockers and competitive inhibitors of angiotensin II are helpful in the diagnosis of clinical renovascular hypertension and in the identification of renin dependent hypertensives. Homeostatic mechanisms leading to maintenance of blood pressure and accumulation of edema in experimental congestive heart failure appear to be dependent on angiotensin II.
Angiographic findigs and prognostic indicators in patients resuscitated from sudden cardiac death.
Authors: Weaver W D , Lorch G S , Alvarez H A , Cobb L A
Published: June 2012

Sixty-four patients with coronary artery disease (CAD) who had been resuscitated from out-of-hospital ventricular fibrillation (VF) underwent cardiac catheterization and angiography. The majority (72%) had a previous history of cardiovascular disease; in the remaining 28%, VF was the first manifestation of CAD. Advanced coronary atherosclerosis was a common finding; 94% of the patients had severe stenoses (70% or greater diameter narrowing) in one or more of the major coronary arteries, and most (70%) had ventricular wall contraction abnormalities. In over half of the patients, coronary anatomy was potentially suitable for complete revascularization. During an average follow-up period of 20.4 months, fourteen of the 64 patients developed a second episode of VF and/or died suddenly (VF/SD). In an attempt to identify characteristics which might be of prognostic value, the clinical, hemodynamic, and angiographic characteristics of this group were compared to those patients who had a single episode of VF and survived during follow-up. Patients who developed recurrent VF/SD had more triple vessel CAD (P less than 0.01), lower ejection fractions (P less than 0.05), and far more severe abnormalities of left ventricular contraction (P less than 0.001). These results indicate that angiographic findings can identify individuals at high risk for recurrent VF and also suggest that myocardial scarring may be an important factor in the initiation of ventricular fibrillation and in its recurrence.
Anterior infarctional changes occurring during mid and late ventricular activation detectable by surface mapping techniques.
Authors: Flowers N C , Horan L G , Johnson J C
Published: June 2012

This is a comparative body surface potential map study of 26 patients with a recent acute anterior myocardial infarction. The mean plus or minus two standard deviations (+/- 2 SD) for the voltage distribution was established at 5 msec intervals throughout the cardiac cycle in 30 normal subjects at each of 142 recording sites. Instances in which a patient's potential distribution fell outside the normal range were analyzed as to location, duration and intensity against the expected time course of ventricular activation. Only four patients had departures from the normal distribution confined to the Q time zone. Twenty patients had not only Q time zone abnormalities, but had areas of both positivity and negativity exceeding +/- 2 SD, which occurred well after 30 msec. Two patients with clearly documented diagnostic Q waves during the first few days of hospitalization had lost these findings by the date of body surface mapping. They did retain, however, departure map findings demonstrating significant abnormalities occurring between 30 and 60 msec after onset of ventricular activation. These changes occurring in the mid and late time zones of the activation sequence are not detectable by conventional electrocardiography or vectorcardiography, yet present a strikingly apparent finding by this technique of analysis and display.
Effects of acute coronary occlusion on the motion and perfusion of the normal and ischemic interventricular septum.
Authors: Kerber R E , Marcus M L , Wilson R , Ehrhardt J , Abboud F M
Published: June 2012

To establish the effect of local and remote myocardial ischemia on interventricular septal motion, 27 open-chest dogs were studied using ultrasound and radioactive microspheres. In 14 dogs the left anterior descending coronary artery was ligated. If the ultrasound beam traversed ischemic septum (proximal LAD occlusion), significant (P less than 0.05) declines in systolic septal velocity (26.4 +/- 2.9 to 6.4 +/- 1.8 mm/sec), and excursion (2.6 +/- 0.3 to 0.7 +/- 0.2 mm) occurred, and systolic thickening was reduced. Similar significant changes were seen when the ultrasound beam traversed nonischemic septum adjacent to the ischemic area (distal LAD occlusion). In 13 additional dogs, circumflex coronary ligation produced posterior ischemia. The mean septal velocity for this group increased significantly (21.8 +/- 2.6 to 26.5 +/- 3.3 mm/sec), as did the septal excursion (2.5 +/- 0.2 to 3.1 +/- 0.4 mm). We conclude that acute LAD occlusion causes a reduction in systolic velocity, excursion, and thickening of both the involved ischemic and the adjacent nonischemic septum. When myocardial ischemia was produced in a part of the ventricle remote from the septum, septal velocity and excursion increased.
Pulmonary regurgitation in large atrial shunts without pulmonary hypertension.
Authors: Liberthson R R , Buckley M J , Boucher C A
Published: June 2012

Seven patients with pulmonary regurgitation (PR), normal pulmonary artery (PA) pressures and large left-to-right atrial shunts are reported. Six had secundum atrial septal defects (ASD) and one had anomalous pulmonary venous drainage. These comprised 4% of 180 patients with atrial shunts and normal PA pressures. Pulmonary regurgitation was diagnosed clinically by mid-frequency diastolic decrescendo murmurs beginning after the pulmonic component of the second heart sound, and diagnoses were confirmed by catheterization. In two patients who had serial preoperative catheterizations over 8 and 16 years, PR progressed in one and was present only on the second study in the other. All patients underwent shunt correction, at which time the pulmonic anulus and artery appeared dilated, but the pulmonic valves were normal and did not require revision. In all patients the PR murmur disappeared after shunt correction alone, and on chest X-ray both PA and overall heart size decreased. Although it is known that pulmonary regurgitation occurs with atrial septal defects and pulmonary hypertension, the present study demonstrates that it also occurs with high flow atrial shunts, in which setting it has different implications and is reversible with shunt correction alone.
The effect of left ventricular pressure or volume overload on ventricular dimension in children. Left ventricular volume determination from one or two ventricular dimensions.
Authors: Villoria G J , Nakazawa M , Marks R A , Jarmakani J M
Published: June 2012

The effect of pressure or volume overload on the geometry of the left ventricle (LV) was determined in order to examine the feasibility and accuracy of LV volume determinations from one minor axis or two dimensions (one minor axis and the longest length). The longest length (LL) and minor axis (MA) in both the anteroposterior (AP) view and lateral (LAT) view were determined from the LV cine silhouette in patients with normal LV volume and pressure (group 1), LV pressure (LVP) overload group (LVP greater than 140 mm Hg, group 2), and LV volume overload group (LV end-diastolic volume greater than 124% of normal, group 3). The ratio of the MA to the LL, which represents the spherical configuration of the LV, was less than "normal" in group 2, and higher than "normal" in group 3. In all groups the LV was less spherical at end-systole than at end-diastole. Additionally, the (MA)3 had a different relationship to true LV volume (biplane LV volume) in the three groups and from diastole to systole in each group. Left ventricular volume calculation from one minor axis was associated with a large error. In contrast, left ventricular volume can be accurately determined from two ventricular dimensions using either the anteroposterior or lateral ventricular image (r larger than or equal to 0.97).
Assessment of left ventricular function in severe aortic regurgitation.
Authors: Johnson A D , Alpert J S , Francis G S , Vieweg V R , Ockene I , Hagan A D
Published: June 2012

Echocardiographic (echo) measurements of left ventricular ejection phase indices--ejection fraction, percent shortening of the minor diameter (%deltaD), and velocity of circumferential fiber shortening (Vcf)--are said to be accurate reflections of their angiographic (angio) counterparts. Most studies correlating echo and angio left ventricular function parameters have included relatively few patients with aortic regurgitation. Echo and angio measurements of left ventricular ejection phase indices thus might not correlate in these patients in whom left ventricular geometry may have been altered due to the volume overload. To test this hypothesis, left ventricular ejection phase indices were determined by angiography and echocardiography and compared in 20 patients with isolated, symptomatic, severe aortic regurgitation. Ejection fraction, %deltaD, and Vcf by LAO cineangiograms and echo were uniformly higher than corresponding measurements from RAO angio, and were often normal in the presence of other indicators of significant left ventricular dysfunction. We conclude that the usual, linear echocardiographic measurement of left ventricular wall motion may not reflect significant myocardial dysfunction in patients with severe aortic regurgitation.
Myocsrdial uptake of technetium-99m stannous pyrophosphate following direct current transthoracic countershock.
Authors: DiCola V C , Freedman G S , Downing S E , Zaret B L
Published: June 2012

The effect of direct current (DC) countershock upon myocardial technetium-99m stannous pyrophosphate (PYP) uptake was studied in 22 dogs. All eight dogs imaged had positive abnormal PYP scintigrams that were usually indistinguishable from experimental infarction. In three animals, additional areas of radionuclide uptake were seen in overlying noncardiac tissue. Left and right ventricular myocardial PYP uptake averaged (+/- SEM) 23 +/- 5 times control and 24 +/- 6 times control, respectively. These activity ratios occurred without reduction in regional myocardial blood flow (RMBF), and were associated with histologic evidence of necrosis. The necrosis was usually epicardial, corresponding to the transmural site of greatest PYP uptake. The magnitude of PYP accumulation and the weight of damaged tissue increased with increasing applied energy. Thus, PYP uptake following DC countershock could result in false-positive interpretation of acute ischemic myocardial infarction. Since RMBF is normal in regions of PYP uptake, the major determinant of radionuclide accumulation is the extent of cellular damage.
Systolic thickening and thinning of the septum and posterior wall in patients with coronary artery disease, congestive cardiomyopathy, and atrial septal defect.
Authors: Corya B C , Rasmussen S , Feigenbaum H , Knoebel S B , Black M J
Published: June 2012

Echocardiographic septal and posterior wall thicknesses and the percent change with systole were measured in 146 patients with the following diagnoses: acute myocardial infarction (40), chronic coronary artery disease (49), congestive cardiomyopathy (8), atrial septal defect (20), and no cardiac disease (29). Mean diastolic thicknesses for the groups of patients with coronary artery disease and congestive cardiomyopathy were not significantly different from normal although there were abnormal values for individual patients within each group. Mean diastolic thickness of the septum was greater than normal for the group with atrial septal defect (P less than 0.02). Wall thinning with systole was associated with acute infarction or ischemia (P less than 0.0001); decreased thickening (less than normal) commonly occurred in patients with acute myocardial infarction, chronic coronary artery disease, and congestive cardiomyopathy. Patients with atrial septal defect had normal thickening with abnormal motion. Results of this study show that 1) systolic thinning is indicative of an acute event; 2) abnormal changes in systolic wall thickening occur commonly in patients with coronary artery disease or congestive cardiomyopathy; and 3) abnormal wall motion may occur without abnormal wall thickening, as the echoes of patients with atrial septal defect indicate.
Premature pulmonary valve opening.
Authors: Wann L S , Weyman A E , Dillon J C , Feigenbaum H
Published: June 2012

Premature opening of the pulmonary valve (opening independent of atrial or ventricular systole) was originally described in a case of sinus of Valsalva rupture into the right atrium. Since that time we have observed five additional cases in which the pulmonary valve opened prematurely. Entities encountered included: 1) constrictive pericarditis; 2) Loeffler's endocarditis; 3) Ebstein's anomaly with tricuspid regurgitation; 4) tricuspid regurgitation following tricuspid valvulectomy, and 5) pulmonary regurgitation accompanied by atrial septal defect. In the first two cases, premature pulmonary valve opening is felt to be due to restriction of diastolic filling of the right ventricle with subsequent early diastolic rise in pressure equalling or exceeding pulmonary artery diastolic pressure. In the latter three cases, the increased volume of blood entering the right ventricle again appeared to result in a rapid rise in initial right ventricular diastolic pressure and to produce premature opening of the pulmonary valve. Premature pulmonary valve opening, therefore, does not appear specific for any particular clinical entity but reflects the relative pressures in the right ventricle and pulmonary artery during diastole.
Recognition of residual postoperative shunts by contrast echocardiographic techniques.
Authors: Valdes-Cruz L M , Pieroni D R , Roland J M , Shematek J P
Published: June 2012

A bedside echocardiographic technique was used to detect and localize residual intracardiac shunts in 26 patients who had surgical repair of septal defects. Contrast echocardiography was performed through central venous and left atrial monitoring catheters at the same time as cardiogreen dye curves. Indicator dilution confirmed residual atrial defects in ten patients and ventricular defects in five. Contrast echocardiography indicated the presence and level of shunting in all 15 patients. Temporary flow through newly implanted septal patches was detected and differentiated from shunting across a true residual defect. The contrast echocardiographic technique using injections through the central venous and left atrial catheters as described detects and localizes right-to-left and left-to-right shunting. It is a safe and reliable method to evaluate residual intracardiac defects postoperatively.
The relationship of patient selection to prognosis following aortocoronary bypass.
Authors: Conley M J , Wechsler A S , Anderson R W , Oldham H N , Sabiston D C , Rosati R A
Published: June 2012

Operative mortality for the first 787 patients who underwent aortocoronary bypass at Duke University Medical Center was 9.7%. Within 699 patients who underwent elective bypass only, operative mortality was 8.8% before January 1, 1972, and 5.4% subsequently. This apparent variation in operative mortality over time was largely a consequence of changing patterns of patient selection, i.e., a two- to three-fold decrease in the prevalence of ventricular dysfunction. Since January 1, 1972, operative mortality for 444 patients with mild or no heart failure who underwent elective bypass only was 5.0%. The 55 patients with left main disease had 12.7% operative mortality. In the 192 patients without left main disease who had one- or two-vessel disease, operative mortality was 1.0%, whereas, 197 patients with three-vessel disease had a 6.6% operative mortality. The 103 patients with three-vessel disease less than 50 years of age underwent operation with a 2.9% mortality. Although these results demonstrate that selected patients may undergo operation with a mortality approaching 1%, it is not clear that only such low risk patients should be offered surgery. Accurate estimates of benefits and risks of aortocoronary bypass surgery are necessary in the management of specific patients.
Accelerated "atherosclerosis". A morphologic study of 97 saphenous vein coronary artery bypass grafts.
Authors: Bulkley B H , Hutchins G M
Published: June 2012

Intimal thickening of uncertain cause has been noted in saphenous vein bypass grafts. To study the development of these changes, 97 vein grafts in 55 autopsied patients were examined by angiography and histology. Significant alterations in the grafts were confined to the intima and included thin layers of circumferential thrombus, concentric fibrous plaque and occlusive thrombus with organization. Circumferential nonocclusive intimal thrombus was present in 36 (73%) postoperative patent grafts. Concentric fibrous plaque, found in all twelve patent late grafts, showed changes characteristic of atheromata, including smooth muscle and foam cells. Intimal fibroelastosis was absent in the grafts, indicating that concentric plaque is not a simple response to increased pressure, or an "arterialization" of the vein. The findings suggest that early appearing concentric intimal thrombus is converted into fibrous plaque, and that this early thrombus is a factor in the development of acclereated "atherosclerosis" in saphenous vein bypass grafts.
Aortic valve replacement combined with myocardial revascularization. Late clinical results and survival of surgically-treated aortic valve patients with and without coronary artery disease.
Authors: Loop F D , Phillips D F , Roy M , Taylor P C , Groves L K , Effler D B
Published: June 2012

From 1967 through 1973, 80 consecutive patients underwent simultaneous aortic valve replacement (AVR) and coronary bypass grafting. Fourteen (18%) experienced no angina pectoris and had no history or electrocardiographic evidence of coronary atherosclerosis. Seven of these 14 had severe multiple vessel disease. All operations were performed under normothermic conditions without coronary perfusion. Seven patients (9%) died during operation. Intra-operative myocardial infarction was documented in eight (10%). After a mean follow-up of 35 months, overall mortality was highest in aortic regurgitation patients [seven of 13 (54%)] compared to aortic stenosis [17 of 54 (31%)] (P less than 0.07), and mixed pathology [1 of 13 (8%)]. Thirty-one of 34 (91%) grafts in 25 patients were patent an average of 12 months postoperatively. After 42 months a 65% actuarial survival was found in the combined AVR and graft(s) series versus a 76% survival in 300 AVR patients proven by angiography not to have severe coronary atherosclerosis.