bluuebunny/crossref_metadata_2025 huggingface dataset:
Echocardiography in congenital and acquired absence of the pericardium. An echocardiographic mimic of right ventricular volume overload.
Authors: Payvandi M N , Kerber R E
Published: June 2012

The purpose of this study was to investigate the echocardiographic effects of absence of the pericardium. Five patients with congenital complete absence of the left pericardium were studied. All had typical chest X-rays, four had cardiac catheterization which excluded any intracardiac shunts, and one had diagnostic pneumothorax. All five had an enlarged right ventricular dimension (RVD): 1.9 +/- 0.1 cm/m2 (normal: less than 1.3 cm/m2) and abnormal interventricular septal (IVS) motion (three Type A, two Type B). Sixteen additional patients were studied after pericardial stripping for a variety of conditions. In none was cardiopulmonary bypass used. Eight of these patients had preoperative echocardiograms; all showed normal IVS motion. After surgery RVD was large in all 16 patients, increasing from 1.0 +/- 0.2 cm/m2 preoperatively to 1.7 +/- 0.1 cm/m2 postoperatively, P less than 0.01. Fourteen of the 16 patients had abnormal IVS motion, nine Type A, and five Type B. We conclude that absence of the pericardium results in echocardiographic abnormalities which mimic those seen in right ventricular volume overload. This may be due to altered cardiac position and motion within the thorax resulting from loss of normal pericardial restraint.
Sound pressure correlates of the Austin Flint murmur. An intracardiac sound study.
Authors: Reddy P S , Curtiss E I , Salerni R , O'Toole J D , Griff F W , Leon D F , Shaver J A
Published: June 2012

Mitral valve motion and pressure correlates of the Austin Flint murmur (AFM) were investigated in nine patients with aortic regurgitation using high fidelity catheter tip micromanometers and the mitral valve echocardiogram (MVE). External phonocardiography demonstrated a mid-diastolic murmur (MDM) in eight subjects and a presystolic murmur (PSM) in five. Maximum intensity of both AFM components was found in the left ventricular (LV) inflow tract; the murmur was not recordable in the left atrium (LA). In two patients, an apparent AFM was recorded in the intracardiac phonocardiogram when absent externally. Only one subject had a significant late diastolic "reversed" or LV to LA gradient; in this patient, presystolic mitral regurgitation was shown angiographically but no PSM was present and MVE revealed absence of atriogenic mitral valve re-opening. In two subjects, a PSM disappeared from the external phono when a "reversed" gradient occurred during the diastolic pause following a ventricular premature systole; this LV to LA gradient was associated with diastolic mitral regurgitation recordable in the left atrial phono. In two patients, LV inflow phono showed the MDM to begin 80-120 msec after the aortic second sound and during the D to E phase of the MVE. The rate of early diastolic mitral valve closure in patients (152 +/- 24 mm/sec) was not significantly different from 13 normals (232 +/- 10 mm/sec). With regard to the genesis of the AFM, the present study concludes: 1) diastolic mitral regurgitation plays no role, and 2) antegrade mitral valve flow is required but simultaneous retrograde aortic flow may also be necessary.
Evaluation of vectorcardiographic criteria for the diagnosis of myocardial infarction in the presence of left ventricular hypertrophy.
Authors: Phillips H R , Starr J W , Behar V S , Walston A , Greenfield J C , Wagner G S
Published: June 2012

Vectorcardiograms (VCG) from a consecutive group of 77 patients with significant aortic valve disease were analyzed. All of the patients had complete left and right heart catheterization with normal coronary arteriograms and normal left ventricular contraction. Thirty-five (46%) patients met VCG criteria for anterior myocardial infarction (AMI-35%) and/or inferior myocardial infarction (IMI-14%). This was a significant increase in false positive diagnosis for both criteria compared to a group of 200 normal volunteers under age 30 and 100 patients with normal hearts by cardiac catheterization (P less than 0.01). It was found that if the VCG diagnosis of myocardial infarction was deferred when the maximal transverse plane magnitude was greater than 1.9 mV, the incidence of AMI false positive diagnosis decreased to 3% and the incidence of IMI false positive diagnosis decreased to 1%. The same rule was applied to the aortic valve disease cohort, a group of 124 patients with documented AMI and a group of 158 patients with IMI. This decreased the sensitivity of the AMI criteria from 93 to 83% and of the IMI criteria from 85 to 77%. The increase in average performance was statistically significant fro the AMI criteria (P less than 0.05) but not for the IMI criteria.
Permanent pacemaker implantation in infants, children, and adolescents. Long-term follow-up.
Authors: Benrey J , Gillette P C , Nasrallah A T , Hallman G L
Published: June 2012

Twenty-four patients in the pediatric age range who underwent implantation of a cardiac pacemaker for treatment of complete atrioventricular (A-V) block were followed for an average of five years (range 1-12 years). The etiology of the A-V block was surgical in 13 cases, congenital in nine, and acquired in two. Twenty patients had symptoms of cerebrovascular insufficiency and four had congestive heart failure. To date, 18 of the 24 patients studied are alive and well. Death occurred in six patients, five of whom had complex congenital heart defects, and one of whom had Refsum's disease. Death probably was caused by complete heart block despite pacemaker treatment in four patients, and congestive heart failure in two. In 18 of the 24 children with disabling complete A-V block, pacemaker therapy provided relief of symptoms and prolonged life.
Influence of acute changes in preload, afterload, contractile state and heart rate on ejection and isovolumic indices of myocardial contractility in man.
Authors: Quinones M A , Gaasch W H , Alexander J K
Published: June 2012

To determine the sensitivity of several isovolumic and ejection phase indices of myocardial contractility to loading, inotropic stimulation and heart rate in man, 14 patients (pts) were studied during cardiac catheterization with simultaneous recordings of left ventricular (LV) pressures and ultrasound dimensions. Measurements were made of instantaneous and mean circumferential fiber shortening velocity (VCF), maximal (max) rate of LV pressure rise (dP/dt), dPHdt divided by end-diastolic circumference [(dP/dt)/C], (DP/dt)/C divided by aortic valve opening pressure [(dP/dt/CP], PEAK CONTRACTILe element velocity (VCE) using total LV pressure, VCE extrapolated to zero total pressure (Vmax), VCE at a developed pressure of 10 mm Hg (VCEDP10) and dP/dt at a common isovolumic developed pressure of 40 mm Hg [(dP/dt)/DP40]. Resulta are expressed in per cent change of the mean for the group. Acute preload increase (8.6% increase in end-diastolic circumference) with volume expansion at constant heart rate in 7 pts produced insignificant changes in VSF, an 8.3% increase in max dP/dt, no change in (dP/dt)/C, a variable response in (dP/dt)/CP, 18% reduction in peak VCE, 16% reduction in Vmax, 14% increase in VCEDP10, and a 10% increase in (dP/dt)/DP40. An acute increase in afterload produced by angiotensin in 8 pts (44% increase in peak stress) led to a 38% decrease in VCF, a 2.5% increase in max dP/dt, no significant change in (dP/dt)/C, a 26% reduction in (dP/dt)/CP, variable responses in peak VCE and Vmax, an 11% increase in VCEDP10 and minor changes in (dP/dt)/DP40. All of the contractility indices were augmented significantly by isoproterenol and atrial pacing. In a given patient, max, dP/dt appears to be useful in the assessment of acute changes in inotropic state since the magnitude of its response to abrupt changes in preload is small and to afterload insignificant. Normalizing max dP/dt for end-diastolic circumference assures better stability during loading with good sensitivity to inotropic stimulation. VCF may be used whenever changes in afterload are minimal. The isovolumic measurements of VCE (regardless of whether total or developed pressure is used) lack sufficient stability during acute changes in loading conditions to warrant their use in the quantitative assessment of acute changes in inotropic state.
Regional Myocardial function in the conscious dog during acute coronary occlusion and responses to morphine, propranolol, nitroglycerin, and lidocaine.
Authors: Theroux P , Ross J , Franklin D , Kemper W S , Sasyama S
Published: June 2012

Regional myocardial function following occlusions of the circumflex coronary artery was studied in unanesthetized dogs using minature ultrasonic crystal pairs implanted subendocardially within the left ventricle for measurement of control, marginal, and ischemic lengths. As early as five beats after coronary occlusion, reduced function was apparent in ischemic zones, and an increase in heart rate occurred (78 to 115 beats/min) at an average of 25 sec. In the control zones, shortening initially increased from a constant end-diastolic length, but later end-diastolic length also increased by 7.5%. Shortening in the marginal zones was reduced by 50% at 90 sec as holosystolic expansion developed in the ischemic zones. On reperfusion, systolic function returned to normal within a few minutes while protodiastolic abnormalities persisted for up to 45 min. With coronary occlusions longer than two minutes most dogs exhibited arousal and further tachycardia; this reaction was prevented by morphine. During two minute occlusions morphine also decreased the heart rate increase by 37%, and marginal segment shortening was improved by 40%. Prior administration of propranolol also decreased heart rate during coronary occlusion and produced similar improvement in marginal segment function; however, in contrast to morphine, there was depression of contraction in the control segments. Nitroglycerin given during coronary occlusion caused decreases in end-diastolic length of all segments and increased shortening in the marginal segment by 28%. Lidocaine administered during coronary occlusion produced a mild depression of myocardial function in all regions of the heart.
Vasodilator therapy for chronic left ventricular failure.
Authors: Kovick R B , Tillisch J H , Berens S C , Bramowitz A D , Shine K I
Published: June 2012

The effects of chronic oral vasodilator therapy were studied in a group of patients with refractory congestive heart failure. Fifteen patients were treated acutely with intravenous sodium nitroprusside and sublingual isosorbide dinitrate. After continuous therapy with nitroprusside and isosorbide dinitrate for up to 72 hours the patients were then placed on isosorbide dinitrate and oral phenoxybenzamine. Hemodynamic responses to nitroprusside, isosorbide dinitrate, and phenoxybenzamine with isosorbide dinitrate were determined. After a mean follow-up of seven months, nine patients who were receiving isosorbide dinitrate and phenoxybenzamine underwent repeat hemodynamic studies. Beneficial effects of acute vasodilator therapy included a significant reduction in pulmonary capillary wedge pressure and systemic vascular resistance, and significant increases in cardiac index and stroke work index. Mean arterial blood pressure and heart rate were unchanged. During the period of chronic vasodilator administration, no other change in basic therapy with isosorbide dinitrate and phenoxybenzamine (3-21 months), the favorable effects observed acutely were maintained. All patients demonstrated symptomatic improvement with minimal side effects. The beneficial hemodynamic responses that are noted with acute vasodilator therapy in patients in advanced congestive heart failure are maintained with oral therapy on a chronic basis.
Combined para-aminosalicylic acid and dietary therapy in long-term control of hypercholesterolemia and hypertriglyceridemia (Types IIa and IIb hyperlipoproteinemia).
Authors: Kuo P T , Fan W C , Kostis J B , Hayase K
Published: June 2012

The hypolipidemic effect of PAS-C-diet treatment was studied in 63 patients with Types IIa and IIb hyperlipoproteinemia for 6-36 months. Serum lipids and body weights of all patients were stabilized by a low cholesterol-saturated fat-refined carbohydrate diet before the initiation of an eight-week placebo-drug single-blind crossover study. During the placebo period the plasma lipids levels, mean +/- SD: cholesterol 355 +/- 63.5 mg%, triglyceride 141 +/- 68.7 mg%, and LDL-cholesterol 279 +/- 56.8 mg% were lowered to 274 +/- 53.1 mg+, 98 +/- 40.6 mg%, and 209 +/- 52.9 mg%, respectively (P less than 0.001 in each instance), with 7.5-11.0 grams of PAS-C/day given in one to three divided doses. In ten patients who have completed three years of treatment similar results were obtained. They showed no tendency to develop drug tolerance. Eight had watery diarrhea during the initial period which promptly subsided with interruption of drug therapy. Reintroduction of PAS-C in smaller dose (4.5 g/day) with gradual increment to effective dosage level was tolerated by all. No hematologic, hepatic, and ophthalmologic abnormalities were demonstrated by periodic monitoring. The hypoplipidemic effect of the drug was found to be diminished by alcohol and caloric excess.
Risk of new myocardial infarction in middle-aged men with manifest coronary heart disease.
Authors: Jenkins C D , Zyzanski S J , Rosenman R H
Published: June 2012

Men incuring coronary heart disease (CHD) during surveillance of an employed population were studied for risk factors associated with additional myocardial infarctions. The coronary-prone Type A behavior pattern measured by a test score, number of cigarettes smoked daily, and serum cholesterol were significantdiscriminators between the 67 men with recurrent CHD and the 220 with but a single clinical CHD event. Diastolic blood pressure and fasting serum triglycerides were not significant discriminators. Statistical analyses directed to possible sources of bias occasioned by the combined retrospective-prospective study design revealed that these problems are negligible and do not alter the findings observed. Type A score appears relatively unaffected by whether the measure was made before or after the initial CHD event. Multivariable discriminant function equations showed Type A score to be the strongest single predictor of recurrent CHD among the variables available. Number of cigarettes smoked and serum cholesterol accounted for additional variance. Future field trials for the secondary prevention of myocardial infarction would be strengthened by consideration of the possible role of Type A behavior.
Multivariate prediction of coronary heart disease in the Western Collaborative Group Study compared to the findings of the Framingham study.
Authors: Brand R J , Rosenman R H , Sholtz R I , Friedman M
Published: June 2012

The Western Collaborative Group Study (WCGS) is a prospective epidemiological study of 3,154 initially well men, aged 39059 years at intake in 1960-61, who were employed in ten participating companies in California. Clinical coronary heart disease (CHD) occurred in 257 men during a follow-up period of eight and one-half years. Coronary heart disease risk is predicted using the additive multiple logistic model with the risk factors: age, cholesterol, systolic blood pressure, hematocrit, ECG status, smoking at intake, and relative body weight. The predicted individual CHS risk levels, using the logistic results derived from the WCGS data, are highly correlated with predicted risk levels using a Framington study (FS) equation for these same risk factors with 12-year follow-up. The observed number of CHS events in the WCGS is not significantly different from the expected number of events derived from the FS logistic equation, after correction of length of follow-up. Multiple logistic analysis of the direct association between CHD incidence and behavior pattern gives an approximate relative risk of 1.9 (P = 0.0006) and 2.1 (P = 0.0015) for Type A compared to Type B men aged 39-49 and 50-59 years, respectively. It is estimated that removal of the excess risk associated with Type A behavior would correspond to a 31% (standard error = 6.6%) reduction of coronary heart disease incidence in the Western Collaborative Group Study population.
Lung water and urea indicator dilution studies in cardiac surgery patients. Comparisons of measurements in aortocoronary bypass and mitral valve replacement.
Authors: Brigham K L , Faulkner S L , Fisher R D , Bender H W
Published: June 2012

We measured transpulmonary indicator dilution curves of 51Cr-erythrocytes, 125I-albumin, 14C-urea, and 3H-water before and six and 24 hours after operation in seven patients undergoing aortocoronary bypass (ACB) and eight patients undergoing mitral valve replacement (MVR). We calculated cardiac output (CO), extravascular lung water (EVLW), the difference between 125I-albumin and 51Cr-erythrocyte distribution volumes (EV albumin), the difference between 14C-urea and 51Cr-erythrocyte distribution volumes (EV urea) and 14C-urea extraction (E) and permeability -surface ares (PS) products. Comparisons between 16 ACB studies and 17 MVR studies showed the MVR group to have a higher EVLW (P less than 0.01). Extravascular lung water decreased after operation. The ratio of EV urea to EV albumin averaged 1.35 in the MVR group and 0.91 in the ACB group (P less than 0.001). 14C-urea E was also higher in the MVR group (P less than 0.05), but PS was similar in the two groups. None of the differences was related to the time that studies were done. We showed that EVLW, calculated using both 125I-albumin and 51Cr-erythrocytes as intravascular indicators and measured blood water content, had a constant relationship to EVLW calculated using only 125-I-albumin as the intravascular indicator and neglecting blood water content, over a broad range of cardiac outputs, hematocrist, and lung water volumes. We conclude that patients with mitral valve disease have an increased distribution volume and E for urea, probably due to hemodynamic changes but possibly due to increased vascular permeability. Extravascular lung water decreases after cardiac surgery regardless of the type of operation. A single intravascular indicator is adequate for estimating extravascular lung water in humans.
Right ventricular growth in a case of pulmonic stenosis with intact ventricular septum and hypoplastic right ventricle.
Authors: Rao P S , Liebman J , Borkat G
Published: June 2012

Adequate growth of the hypoplastic right ventricle in a patient with severe pulmonary stenosis with an intact ventricular septum was documented after pulmonary valvotomy in infancy. It is postulated that the growth of the ventricular chamber is largely the result of pulmonary regurgitation resulting from successful pulmonary valvotomy. Based on this and the observations of others on the growth of the hypoplastic right ventricle in pulmonary atresia (with intact septum) cases, an organized approach to eventual total surgical correction is recommended.
Human ventricular refractoriness. Effects of cycle length, pacing site and atropine.
Authors: Guss S B , Kastor J A , Josephson M E , Schare D L
Published: June 2012

The effective refractory period of the right ventricle (ERP-V) was measured in 27 patients during atrial or ventricular pacing using the ventricular extra stimulus method. Pacing was conducted with impulses of 1.5-2 times diastolic threshold. The ERP-V was directly related to the basic cycle length (BCL) although the ERP-V was always greater for atrial pacing than for ventricular pacing at a given BCL. The ratio ERP-V/BCL was greater at shorter cycle lengths indicating that a larger fraction of the cycle was refractory at faster heart rates. The ratio ERP-V/QT interval did not change over a range of BCLs, but the ratio was larger for atrial pacing (.77 +/- .05 SD) than for ventricular pacing (.60 +/- .05). Atropine (1 mg i.v.) was given to six patients. The drug did not affect the ERP-V in six of eleven determinations, prolonged ERP-V twice and shortened it slightly three times. Measurements were reproducible over an hour but varied at a given BCL when measured on separate days. Asymptomatic repetitive beating occurred in seven of 27 patients when the premature stimulus was within 20 msec of the ERP-V. The effective refractory period of the right ventricle in man can be determined reproducibly and with safety. Changes induced by various perturbations parallel results from in vitro single cell and myocardial studies.
Mitral valve prolapse in one hundred presumably healthy young females.
Authors: Markiewicz W , Stoner J , London E , Hunt S A , Popp R L
Published: June 2012

Clinical, electrocardiographic, phonocardiographic, and echocardiographic examinations were performed in 100 presumably healthy young females. Treadmill testing and ambulatory electrocardiographic monitoring were performed in a selected group of these subjects. Phonocardiograms, recorded with the subjects supine at rest, after inhalation of amyl nitrite, and in the upright position, revealed a 17% incidence of nonejection clicks and/or late or mid- to late systolic murmurs (PHONO-MSCLSM). Echocardiographic studies were performed in the second, third, fourth, and fifth intercostal space with emphasis on the importance of transducer angulation on the chest. Studies obtained with the transducer perpendicular to the chest in the sagittal plane, or pointing cephalad at a time when both mitral leaflets and left atrium are recorded, are optimal to study the mitral valve systolic motion. With the transducer in this position, 21 subjects were found to have pansystolic or late systolic prolapse, as previously defined on the echocardiogram. The presence of these echocardiographic findings was statistically related to the presence of PHONO-MSCLSM. Other echocardiographic patterns were identified and their relation to PHONO-MSCLSM and transducer position is discussed. Ten subjects with both echocardiographic evidence of mitral valve prolapse and PHONO-MSCLSM were identified (group EP), while 18 other subjects had either echocardiographic or phonocardiographic findings suggestive of mitral valve abnormality (group EorP). Seventy-two subjects had no abnormality (group noEP). The incidence of various clinical, electrocardiographic, and echocardiographic findings in these three groups was determined. Some findings said to be common in patients with proven mitral valve prolapse were seen more frequently in group EP subjects. Echocardiographic and phonocardiographic findings suggesting mitral valve abnormalities were found more commonly than expected in a population of presumably healthy young females.
Spectrum of echocardiographic findings in bacterial endocarditis.
Authors: Roy P , Tajik A J , Giuliani E R , Schattenberg T T , Gau G T , Frye R L
Published: June 2012

Forty-seven echocardiograms were obtained in 32 patients with bacterial endocarditis. Preexistent abnormalities were found in 14 patients. In five of them thought to have bacterial endocarditis on normal valves, echocardiography showed mitral stenosis (one), bicuspid aortic valve (two), and prolapse of mitral valve (two). Definite vegetations were seen in 22 patients--on the aortic valve in seven, the mitral valve in 12, and both valves in three. Ten patients had milder changes suggestive but not diagnostic of vegetations. In 12 patients, surgery confirmed the echocardiographic findings. Fourteen had systemic embolic episodes and all had echocardiographic evidence of vegetations. Abnormalities secondary to bacterial endocarditis, other than vegetations, were common. Twenty-one patients had left ventricular volume overload. Ten had a flail posterior leaflet of the mitral valve, three of which were confirmed surgically. Eight had abnormal coarsely fluttering echoes in the left ventricular outflow tract consistent with a prolapsing aortic valve or underlying aortic vegetations; four were confirmed by surgery. Five had signs of severe aortic regurgitation of recent onset (premature mitral valve closure) and all had confirmation by surgery. Echocardiographic abnormalities persisted after successful medical treatment. We conclude that echocardiography is helpful in patients with bacterial endocarditis. It permits recognition of unsuspected preexistent lesions and the characteristic vegetations, as well as the extent and nature of valvular damage secondary to bacterial endocarditis. However, echocardiography does not differentiate between active and healed lesions.
Reflex vasodilation induced by coronary angiography in human subjects.
Authors: Zelis R , Caudill C C , Baggette K , Mason D T
Published: June 2012

In order to evaluate the reflex peripheral vascular effects of coronary arteriography, forearm blood flow was measured plethysmographically and forearm vascular resistance calculated before and during coronary angiography with Hypaque-M, 75%, and Renografin-76. The injection of Hypaque into the left coronary artery resulted in a forearm vasodilation which could not be duplicated by an injection of a comparable amount of contrast into the ascending aorta, three centimeters above the coronary ostia. Forearm blood flow rose from 2.95 to 5.41 ml/min/100 ml (83.4%) and forearm vascular resistance fell from 35.8 to 19.9 mm Hg/ml/min/100 ml (44.4%). Renografin injected into the left coronary artery resulted in less forearm vasodilation (21% increase in forearm blood flow and 32% decrease in forearm vascular resistance). When coronary arteriography was repeated following injection of atropine into the brachial artery, no forearm vasodilation occurred. It is suggested that in human subjects myocardial or coronary artery receptors can be activated by the intracoronary injection of iodinated contrast media which results in a forearm vasodilation.
Measurement of foot artery blood pressure by micromanometry in normal subjects and in patients with arterial occlusive disease.
Authors: Bollinger A , Barras J P , Mahler F
Published: June 2012

Blood pressure was measured continuously in the posterior tibial or dorsalis pedis arteries using an isovolumetric system (steel cannulas of 0.18 mm, external diameter). The systolic values in the ankle arteries of 13 normal subjects at rest (154.3 +/- 22.3 mm Hg) exceeded the systolic arm pressure (128.9 +/- 20.1 mm Hg, P less than 0.001), while diastolic values (69.9 +/- 8.7 mm Hg) were not significantly different from the arm pressure. In 13 patients with arterial occlusive disease (AOD) the dicrotic notch, normally situated close to the footpoint of the downslope, was either displaced upward or abolished. Both mean systolic and diastolic values (94.9 +/- 35.9 mm Hg and 62.5 +/- 18.5 mm Hg, respectively) and also mean pressure amplitude were reduced compared to the corresponding arm values (158.5 +/- 28.2 mm Hg and 87.7 +/- 6.0 mm Hg, respectively, all P less than 0.001). Comparison between the systolic pressure values measured by micromanometry and by an indirect technique using Doppler ultrasound showed a good correlation (r = 0.87). During postocclusive reactive hyperemia, the initial pressure values were markedly diminished in normal subjects and reached control values within 40 sec. In patients with AOD, however, this reduction in pressure was more pronounced and prolonged. Flow measurements using plethysmography showed flow diversion from the foot to the calf as long as pressure values ranged below 40 mm Hg. This almost painless method appears useful for experimental and diagnostic studies in low pressure areas of the peripheral circulation.
Late postoperative hemodynamic results and cineangiocardiographic findings after Mustard atrial baffle repair for transposition of the great arteries.
Authors: Clarkson P M , Neutze J M , Barratt-Boyles B G , Brandt P W
Published: June 2012

Forty-nine patients with transposition of the great arteries who underwent a Mustard atrial baffle repair between 1964 and 1971 were assessed late postoperatively. There have been five late deaths: two related to baffle obstruction, two from noncardiac causes, and one sudden and unexpected. Hemodynamic data were available in 42 patients and autopsy in four. Obstruction of the lower venous channel was not encountered. Three patients had severe obstruction of the upper venous channel and in four there was mild restriction. Two patients had severe pulmonary venous obstruction resulting in late death; mild asymptomatic obstruction could not be excluded with certainty in six patients. Tricuspid incompetence was infrequently encountered in patients with an essentially intact ventricular septum. Left ventricular outflow tract obstruction was found in eight patients. In three it was present after satisfactory but incomplete surgical relief and in five it had not been recognized prior to operation. In only one of the latter patients was the obstruction important. Seventeen patients were operated on prior to one year of age. While baffle obstruction was confined almost entirely to these patients, the five youngest patients, aged one to nine weeks at operation, had adequate pulmonary and caval compartments at restudy two to three years later.
Double ventricular parasystole. Supernormal phase of conduction as a mechanism of intermittent parasystole. Report of a case.
Authors: Hiejima K , Poh T D
Published: June 2012

A rare case of spontaneous double ventricular parasystole was studied in depth, together with a critical review of similar cases in the literature. The discussion was focused on 1) the variation of the shortest interectopic interval (SIEI), 2) entrance block and its failure, 3) supernormality as a mechanism of intermittence, and 4) effects of lidocaine and atropine on such an arrhythmia. In double ventricular parasystole a greater than usual variation in the SIEI tended to occur in one of the two parasystolic groups. If, however, such variations were too great in the face of otherwise parasystolic rhythm, presence of intermittence was confirmed. A temporary loss of the entrance block was deemed primarily responsible for the intermittency. That is to say, invasion, discharge, and resetting of one parasystolic focus by another parasystolic impulse during the supernormal phase of the ventricle was considered the cause of an intermittence. In a strict sense, this is the first report in the literature in which the supernormality was clearly indicated as one mechanism of intermittent ventricular parasystole. The advantage of the concept of double ventricular parasystole as compared to single parasystole in defining such a mechanism is stressed.
Prospective observations in patients with chronic bundle branch block and marked H-V prolongation.
Authors: Dhingra R C , Denes P , Wu D , Wyndham C R , Amat-y-Leon F , Towne W D , Rosen K M
Published: June 2012

Eighteen of 388 patients with chronic bundle branch block, studied electrophysiologically and followed prospectively, had H-V intervals of 80 msec or greater. Five patients were functional class I, five class II, seven class III, and one class IV. Follow-up ranged from 103 to 1919 days (mean 711 +/- 118). Three patients needed permanent pacing for the following indications: sino-atrial block, sinus bradycardia post-cardiac surgery, and 2 degrees block distal to the His bundle. Six patients died, three suddenly, and three nonsudden. The five initially asymptomatic patients are alive and without pacemakers (mean follow-up 732 +/- 139 days). Although marked H-V prolongation was associated with high morbidity and mortality in this small series, this was only in patients with symptomatic heart disease. Asymptomatic patients (five patients) had a benign clinical course. Prophylactic pacing would probably not modify clinical course in the former group, and is probably not indicated in the latter group. Longer follow-up will be needed for definitive prognostication.
Interobserver variability in coronary angiography.
Authors: Zir L M , Miller S W , Dinsmore R E , Gilbert J P , Harthorne J W
Published: June 2012

Four experienced coronary angiographers (two radiologists and two cardiologists) independently assessed the location and degree of coronary artery stenosis, and the location and degree of left ventricular wall motion abnormalities in 20 coronary angiograms. Marked interobserver variability was noted in quantifying percent coronary artery stenosis and degree of left ventricular wall motion abnormalities. For example, in only 13/20 (65%) of the coronary angiograms did all observers agree about the significance of a stenosis (defined as greater than 50% in diameter luminal narrowing) in the proximal or mid left anterior descending coronary artery. In 3/20 (15%) angiograms there was disagreement by at least one observer about the significance of lesions noted in the main left coronary artery. The ventricle was divided into five segments and the degree of wall motion abnormality graded into six categories of increasing severity from normal to dyskinesis. There was a 42% mean disagreement among all four observers where a disagreement between observers was defined as any difference in grading wall motion abnormalities. Interobserver variability reveals a significant limitation of coronary angiography.
Mitral valve prolapse in children: a problem defined by real-time cross-sectional echocardiography.
Authors: Sahn D J , Allen H D , Goldberg S J , Friedman W F
Published: June 2012

The cross-sectional echocardiographic features of mitral valve prolapse were defined in 26 children (ages 2-18 years) using a real-time, multiple-crystal ultrasound scanner. In each patient the physical findings of the mitral valve click-murmur syndrome were present and mitral valve prolapse had been diagnosed previously by conventional single crystal echocardiography. Mitral prolapse occurred in a familial setting in eight patients and was associated with the Marfan syndrome in five. Real-time two-dimensional echocardiography uniformly disclosed maximum mitral arching and the superior-posterior prolapse. These visual observations were confirmed by M-mode recordings derived from single elements within the array of 20 crystals. The method allowed a complete M-mode description of the phasic motion of the entire mitral apparatus and observations of the spectrum of prolapse from discrete late systolic prolapse to "hammock-like" holosystolic prolapse. Further, the recording of multiple systolic M-mode lines occurred when the ultrasound beam intersected the arched leaflets more than once. Pseudosystolic anterior motion was observed often and resulted clearly from a superimposition of echoes from the mitral annulus and from the posterior-superiorly arched prolapsed leaflets. A major finding in 22 patients was the association with prolapse of biconvex enlargement of the aortic sinuses of Valsalva and a significant increase in the diameter of the aortic root. Aortic root dilatation was most marked in, but not confined to, patients with the Marfan syndrome and was a prominent finding in six patients with minor musculoskeletal abnormalities. The presence of aortic root dilatation in children with normal body habitus raises important questions concerning the generalized nature of an abnormality of cardiac connective tissue in patients with mitral prolapse. The cross-sectional approach significantly enhances the noninvasive evaluation of mitral valve prolapse and provides an explanation for many of the single crystal observations reported previously.
M-mode echocardiography in the evaluation of patients for aneurysmectomy.
Authors: Dillon J C , Feigenbaum H , Weyman A E , Corya B C , Peskoe S , Chang S
Published: June 2012

In order to determine whether echocardiography could be useful in predicting surgical mortality of aneurysmectomy, preoperative condensed M-mode echocardiographic scans were taken from both mid (standard position) and low (nearer apex) intercostal spaces and/or from the subxiphoid area in eighteen patients who were sent to surgery for aneurysmectomy. Eleven of the eighteen patients survived aneurysmectomy. All eleven had mid left ventricular dimensions less than 3.3 cm/m2 and low dimensions of 3.8 cm/m2 or less. Of the seven patients who died, the mid and low left ventricular dimensions exceeded 3.3 cm/m2 and 3.8 cm/m2, respectively, with one exception. The combination of abnormal mitral valve closure, a dilated mid dimension and lack of normal motion in opposing wall segments was only seen in six nonsurvivors. Echocardiography can provide information concerning the state of the left ventricle in patients with ventricular aneurysms and these findings may be helpful in predicting surgical mortality for aneurysmectomy.
Platelet hyperaggregability in idiopathic recurrent deep vein thrombosis.
Authors: Wu K K , Barnes R W , Hoak J C
Published: June 2012

Studies of platlet function were performed in 30 patients with idiopathic recurrent venous thrombosis. Evidence of platelet hyperactivity was found in 14 patients who exhibited spontaneous platelet aggregation and in 13 patients who had evidence of circulating platelet aggregates. No other differences in clinical characteristics or coagulation parameters could be elucidated between these two subgroups. In nine patients who had 51Cr-labeled platelet survival studies, there was a good correlation between the platelet hyperactivity and shortened platelet survival. Spontaneous platelet aggregation was inhibited both in vivo and in vitro by aspirin. In addition, the circulating platelet aggregates were normalized by combination treatment with aspirin and dipyridamole. The results indicate that the idiopathic recurrent venous thrombosis patient population could be differentiated by the platelet function tests into subgroup I, in which no platelet abnormality could be detected, and subgroup II, where platelet hyperaggregability was present. These results indicate that the role of platelets should be considered in the pathogenesis of recurrent venous thrombosis and therapy with agents which inhibit platelet aggregation may be beneficial in the patients with platelet hyperaggregability.
The effects of delta-9-tetrahydrocannabinol (cannabis) on cardiac performance with and without beta blockade.
Authors: Kanakis C , Pouget J M , Rosen K M
Published: June 2012

Systolic time intervals (STI) were measured in ten healthy male volunteers before and after intravenous (i.v.) administration of 25 mug/kg delta-9-tetrahydrocannabinol (delta-9-THC). Mean +/- SEM heart rate increased 32 +/- 7 beats/min, while systolic and diastolic blood pressures were unchanged after delta-9-THC. Total electromechanical systole lengthened 17 +/- 4.2 msec, left ventricular ejection time (LVETc) prolonged 24 +/- 4.0 msec and pre-ejection period (PEP) shortened 17 +/- 5.1 msec after delta-9-THC. All of these changes were significant (P less than 0.01). In nine other subjects who underwent prior beta adrenergic blockade, similar but less marked changes were noted in heart rate, blood pressure, and STI after delta-9-THC. The shortening of PEP after delta-9-THC was only 9 msec (NS) in beta blocked subjects. Thus, delta-9-THC significantly increased heart rate, shortened PEP and prolonged LVETc without any change in afterload. Beta adrenergic blockade prevented significant shortening of PEP and blunted other responses. These findings suggest that delta-9-THC enhanced cardiac performance. Partial inhibition of this effect was achieved with prior beta adrenergic blockade.
Infantile cardiomyopathy with histiocytoid change in cardiac muscle cells. Report of six patients.
Authors: Ferrans V J , McAllister H A , Haese W H
Published: June 2012

Clinical and pathologic findings are presented in 14 patients (six newly reported, eight described previously), all children ranging in age from 6 to 24 months, with a clinicopathologic syndrome termed "infantile cardiomyopathy with histiocytoid change in cardiac muscle cells." This syndrome is manifested clinically by severe, eventually fatal cardiac arrhythmias, and is characterized pathologically by cardiac hypertrophy and by a distinctive type of focal degeneration of the muscle cells, which lose their myofibrils, undergo marked mitochondrial hyperplasia, become rounded in shape and enlarged, and resemble histiocytes. Evidence is presented to support the conclusions that these manifestations are those of a cardiomyopathy, that cardiac hypertrophy precedes the onset of the clinical features, that the focal degeneration is likely to be a cause rather than a consequence of the arrhythmias, and that the latter develop only in the late stages of the disorder. The etiology of this cardiomyopathy remains unclear.
E-type prostaglandins: a new emergency therapy for certain cyanotic congenital heart malformations.
Authors: Olley P M , Coceani F , Bodach E
Published: June 2012

Prostaglandin E2 (PGE2) has been used to maintain patency of the ductus arteriosus in four neonates with cyanotic congenital heart disease due to obstructive right heart malformations. PGE2 was infused prior to surgery, and in three patients, during surgery until a satisfactory aorto-pulmonary shunt was established. PGE2 produced consistently an immediate and persistent rise in arterial oxygen saturation, which could be ascribed to dilation of the ductus arteriosus. No major side effects occurred, except for pyrexia in two infants. All patients recovered well from surgery. We propose this treatment as preparation for surgery in any infant with congenital heart defects and ductus-dependent pulmonary blood flow. The same treatment may be useful preoperatively in patients with aortic interruption who also depend on continued patency of the ductus for blood supply to the lower half of the body.
De subitaneis mortibus. XVII. Multifocal stenoses due to fibromuscular dysplasia of the sinus node artery.
Authors: James T N , Marshall T K
Published: June 2012

The sinus node artery was focally narrowed by fibromuscular dysplasia in two examples of sudden unexpected death reported here. Although both cases had additional histological abnormalities in the conduction system of the heart, the more striking feature was the focal fibromuscular dysplasia. These findings are discussed in relationship to a large number of similar examples of focal fibromuscular dysplastic narrowing of the sinus node artery observed in other victims of sudden unexpected death, considering some possible mechanisms for lethal electrical instability of the heart and also the possible pathogenesis of such fibromuscular dysplasia.
Familial atrial septal defect with prolonged atrioventricular conduction.
Authors: Pease W E , Nordenberg A , Ladda R L
Published: June 2012

This report describes a family with frequent recurrence of congenital heart disease in multiple generations. Eight members had atrial septal defect (ASD) of the fossa ovalis type and seven members had other forms of congenital heart disease. One branch of the pedigree showed a predominance of ASD with prolonged atrioventricular (A-V) conduction and initially suggested an autosomal dominant gene effect. A variety of other forms of congenital heart disease were found in several first degree relatives of those with ASD as well as in more distant relatives. The variability of congenital heart disease in this pedigree is compatible with the polygenic mode of inheritance. Definition of the inheritability of congenital heart disease in a specific family has important consequences in the determination of the recurrence risks for all family members.
Protection of the sinus node in Mustard's operation.
Authors: El-Said G M , Gillette P C , Cooley D A , Mullins C E , McNamara D G
Published: June 2012

The occurrence of dysrhythmias after the Mustard operation for transposition of the great arteries was compared in 70 patients operated upon before and 58 patients operated upon after January 1972 when surgical modifications aimed at preserving the sino-atrial node and its arterial supply were initiated. The surgical modifications included changing the site of the superior vena cava (SVC) cannulation away from the SVC-right atrial junction, incision into the right atrial wall anterior to the sulcus terminalis, and sewing of the superior part of the baffle patch away from the sino-atrial node area. A significant decrease in the incidence of dysrhythmias occurred in the group of patients operated upon after the surgical modifications. The modifications in surgical technique have reduced but not avoided dysrhythmias.
Regional myocardial perfusion during atrial pacing in patients with coronary artery disease.
Authors: Schmidt D H , Weiss M B , Casarella W J , Fowler D L , Sciacca R R , Cannon P J
Published: June 2012

Regional myocardial perfusion (RMP) was measured with 133xenon and a multiple-crystal scintillation camera at rest and during atrial pacing in 24 patients with normal coronary arteriograms or less than 50% lesions, Group I, and in 24 with significant (greater than 50% lesions) left coronary artery disease (CAD), Group II. Pacing induced increases in the double product (DP) of heart rate and systolic blood pressure, an index of myocardial oxygen consumption, were not different for Groups I and II. In Group I average mean LV perfusion rate was subnormal at rest but rose from 49 to 73 ml/100 g-min during pacing to 150/min without angina. A response index (RI), (deltaMP X 10(3)/deltaDP), averaged 2.93. Twenty patients in Group II developed angina during pacing. The average mean LV perfusion rose less than in Group I, from 48 to 64 ml/100 g-min (P less than 0.05) and the average RI, 1.76, was lower (P less than 0.01). In 19 of these patients, average RMP distal to the major coronary lesion increased from 46 to 58 ml/100 g-min; this increase during pacing was significantly less than in the remainder of the LV of 48 to 66 ml/100 g-min (P less than 0.05). Average regional RIs were 1.39 and 2.18, respectively. In three patients the presence of collaterals termed adequate by radiological criteria was not associated with preferential decreases in the distal regional RI. The data support the hypothesis that in some patients with CAD, angina pectoris results when an obstructive coronary lesion restricts the total or regional myocardial blood flow response to an increased rate of myocardial oxygen consumption.
Myocardial reperfusion in acute experimental ischemia. Beneficial effects of prior treatment with steroids.
Authors: da Luz P L , Forrester J S , Wyatt H L , Diamond G A , Chag M , Swan H J
Published: June 2012

To test the hypothesis that prior steroid administration may enhance the mechanical and metabolic response to myocardial reperfusion, regional myocardial function (Hg-in-silastic length gauges), transmyocardial lactate balance and K+ difference were measured in 12 control and 13 treated (30 mg/kg methyl-prednisolone, 30 to 60 min postocclusion) dogs. At three hours of ischemia, systolic shortening in the ischemic segment was greater in treated dogs (40.6% vs. 12%, P less than 0.05), while both lactate balance and K+ arteriovenous difference became positive. Lactate balance and K+ difference remained negative in the untreated animals. After three hours of occlusion and one hour of reperfusion, recovery of shortening was significantly greater in the treated animals (75.9 vs. 31.6%, P less than 0.05). In addition, while lactate balance remained negative among the control dogs, it further improved in the treated dogs. Thus, steroid administration during experimental coronary occlusion impedes the progression of ischemia and is additive to reperfusion in reversing ischemic dysfunction.