Right ventricular endomyocardial fibrosis. Diagnosis and management.

The clinical course, noninvasive and invasive diagnostic findings in 4 patients (pt) with endomyocardial fibrosis are reported. All patients (16-50 years) were in functional class III-IV (NYHA). Central venous pressure with large a- and v-waves was elevated in all; liver enlargement and peripheral edema were also noticed in all pts, and ascites in 3. An apical 2/6 systolic murmur was present in 2, and a right parasternal pansystolic murmur 2-4/6 with positive Carvallo's sign in all pts. ECG was non-specific and chest x ray showed right atrial enlargement in every case. A right-sided diastolic plateau which was higher than left ventricular end-diastolic pressure was present in all pts. Echo-, angiocardiography and computed tomography of the heart revealed obliteration of the right ventricular cavity, predominantly localized at the apex. Two pts who underwent endocardial resection and tricuspid valve replacement are alive and well after 9 and 8 years, respectively. One pt died early in the postoperative period and one died waiting for surgical therapy. In conclusion, echo-, angiocardiography and computed tomographic findings are diagnostic. A satisfactory differentiation from other cardiac disorders with restrictive hemodynamics and right-sided heart failure is possible.

Constrictive endocarditis. Report of a case with successful surgery.

An 18-year old white youth presented with severe right heart failure and was found to have an obliterated and funnel-shaped right ventricle, massive tricuspid regurgitation, and mitral regurgitation. The haemodynamic findings were those of cardiomyopathy with obliteration on the right side. He underwent surgery consisting of decortication and peeling off of a thickened right ventricular endocardium, tricuspid valve replacement, and mitral valve repair. After surgery there was pronounced haemodynamic as well as clinical improvement. The pathological picture was that of constrictive endocarditis. We recommend this method of treatment for patients with obliterate cardiomyopathy on either side of the heart.

Electrophysiologic effects of lidocaine in children.

The effects of intravenous lidocaine on the refractory periods of the atrium, AV node and right ventricular myocardium were studied using His bundle recordings and the extrastimulus technique with and without atrial and ventricular pacing. The drug was administered in an intravenous bolus dose of 1 mg/Kg followed by an infusion of 100 micrograms/Kg/min. The AH, HV intervals and resting sinus cycle length as well as functional and effective refractory periods of atrium, AV node and right ventricle were measured before and 5 min afrer bolus injection of lidocaine. Neither of the refractory periods nor AH and HV intervals changed significantly following administration of lidocaine. The result of this first study in children is in agreement with previous reports of the effects of lidocaine on the cardiac conduction system in adults.

Association of atrioventricular valve atresia with single ventricle, truncus arteriosus communis and transposition. A basic reorientation in the approach to the definition of congenital heart defects.

A heart specimen is presented which showed a rare combination of atrioventricular valve atresia with single ventricle, truncus arteriosus communis with an anteriorly placed trunk, ie transposition. Because of the problems involved in the classification of this heart, the types of single ventricle are revised with particular attention to the rare cases of atrioventricular valve atresia and single ventricle reported in the literature. Also the rare type of truncus arteriosus communis with truncoatrioventricular valve discontinuity is excluded from the so-called transposition complexes, and properly classified as a form of truncus. The literal meaning of transposition is stressed and it is urged to approach congenital heart defects in a purely anatomic sense with definition of each segment as accurately as possible. Thus the present confusion in terminology and further plethora of new terms are avoided.

Pathology of chronic rheumatic mitral valvulitis in Iran and its surgical implications.

Sixty-two consecutive surgically removed chronic rheumatic mitral valves were classified and tabulated according to their pathological features in relation to age and sex of the patients. The pathological features of the valves are quite different from the cases seen in Western hemisphere. Three types of gross pathological features are described. First is fibrous stenotic type which has very thick cusps and extremely short chordae tendineae. It is the most frequent rheumatic vavle seen in children, and majority of the valves show pure stenosis, for which probably open commissurotomy is the procedure of choice. Those which have a combination of stenosis and insufficiency usually require valve replacement. The second is the elastic insufficient type, which has a unique gross pathological feature, consisting of a remarkable elasticity and moderately thickened cusps. A valve replacement or valve repair when feasible is the treatment of choice for this type. The third is the calcific stenotic type. In this type the cusps are moderately thickened with short chordae tendineae with various degrees of calcification. This type is seen usually in the 4th decades of life and is more frequent in males. This type of valve must be treated either by open commissurotomy in order to eliminate the risk of embolization of calcific material or with valve replacement.

Cardiovascular emergencies in pediatrics.

This article dicusses emergencies of cardiovascular origin in infants and children. Particular attention is given to congestive heart failure, hypoxic states, arrhythmias, cardiac tamponade, perinatal cardaic emergencies and conditions simulating cardiac crises. An outline of etiologic and therapeutic approach is included, and guidelines are provided for the practitioner who is called to care for such emergency situations.

A morphometric study of the aortomitral valve apparatus in the embryonic and adult chicken heart. Implications on the developmental hypotheses of the transposition of the great arteries.

A comparative morphometric study was performed on the aortomitral valve apparatus of the embryonic and adult chicken hearts. It was found that the thickness of the aortic and mitral valve cusps diminishes dramatically as the embryo matures, however the relative length of the aortic valve, mitral valve and subaortic conus remains constant. A comparison of the aortomitral valve apparatus in chicken and man revealed that the subaortic conus is not completely resorbed in the fowl, whereas this process is well documented in the mammalian hearts. The implications of this observation on "the differential conal growth hypothesis" of transposition of the great arteries are discussed.

Regression of pulmonary hypertension after mitral valve surgery in children. Operative management of rheumatic mitral valve disease.

Forty-one children with advanced chronic rheumatic disease of the mitral valve had preoperative and postoperative hemodynamic studies. Twenty-three cases had open mitral commissurotomy, and 20 had mitral valvular replacement. After surgery the average pulmonary arterial systolic pressure in the group with valve replacement decreased from 78 to 42 mm Hg, the pulmonary vascular resistance decreased from 974 to 313 dynes sec cm 5, and the cardiac index rose from 2.29 to 4.15 L/min sq m. In the group with mitral commissurotomy, the average pulmonary arterial systolic pressure decreased from 90 to 63 mm Hg, the pulmonary vascular resistance decreased from 1,201 to 616 dynes sec cm-5, and the cardiac index rose from 2.5 to 3.5 L/min sq m. While all patients with mitral valve replacement showed a drop in pulmonary arterial pressure, the postoperative pressures were higher after commissurotomy in four patients, two of whom required a second operation of valve replacement. The study shows that in children, even severe degrees of pulmonary hypertension secondary to mitral valve abnormality is corrected.

The vectorcardiogram as an aid to diagnosis in left ventricular-right atrial communication.

Frank vectorcardiograms (VCGs) in four patients with left ventricular-right atrial (LV-RA) communication were analyzed and compared with published values of VCGs of normal individuals and those from a group of patients with membranous ventricular septal defect. It was observed that the QRS-loops in the frontal and sagittal planes of the patients with LV-RA communication are shifted more superiorly than usual. Thus, almost 50% of the QRS-loop area was superior to the X- and Z-coordinates in the frontal and sagittal planes, whereas in the controls less than 10% of the frontal and sagittal plane QRS-loops were superior to the horizontal axes. The QRS-loops of patients with LV-RA communication thus seem to be halfway between normal and endocardial cushion defect loops. An unusual degree of superior orientation of the QRS-loop in a patient with clinical findings of a ventricular septal defect should arouse suspicion of a LV-RA communication. Also in patients with an isolated ventricular septal defect but with an exaggerated superior orientation of the QRS-loop in the frontal and sagittal planes, the interatrial septum should be examined at the time of operation to exclude the possibility of an associated LV-RA communication.

Simplified vectorcardiographic method for assessment of pulmonary arterial pressure in children with chronic rheumatic mitral valve disease.

We previously reported that pulmonary artery pressures can be assessed in children with chronic rheumatic mitral valve disease by measuring right maximum spatial vector from Frank vectorcardiogram. To simplify the calculation, pulmonary artery systolic pressure was correlated with maximum negative deflection on Frank scalar X-lead (SX), maximum negative deflection on scalar Z lead (SZ), sum total of SX and SZ (SX+SZ) and combined SX and SZ. The patient material consisted of 30 children with chronic rheumatic mitral valve disease, aged 8-14 1/2 years. Eleven were male and 19 were female. Sixteen had mitral stenosis, 8 had mitral regurgitation, and 6 had combined mitral regurgitation and stenosis, documented by cardiac catheterization and angiocardiographic study. The results showed a significant correlation between pulmonary artery systolic pressure and SX (r=0.782). As calculation of SX is considerably easier and less time consuming than that of right maximum spatial vector, this simplified method is preferable to right maximum spatial vector for prediction of the pulmonary artery systolic pressure of children with pulmonary hypertension due to chronic rheumatic mitral valve disease.

Calcified right ventricular fibroma causing outflow obstruction. Report of a case with successful excision.

A 5-year-old boy with clinical findings of pulmonic stenosis was found to have a large calcified mass in the right ventricular outflow region and a gradient of 120 mm Hg between the right ventricle and the pulmonary artery. At surgery, an ovalshaped tumor attached to the interventricular septum and obstructing the right ventricular outflow tract was removed. The child survived and is doing well. Histologically, the tumor had the characteristics of fibroma. A hemodynamic study three months after surgery showed almost complete abolishment of the gradient. To our knowledge this is the fifth reported case of calcified right ventricular fibroma with successful operation. In childhood intracardiac calcifications, together with obstruction, are highly suggestive of this lesion.

Transatrial closure of ventricular septal defect in corrected transposition of the Great Arteries.

The repair of ventricular septal defect (VSD) in corrected transposition of the great arteries has presented many technical problems and was associated with a high mortality. Transatrial closure of the VSD in this malformation obviates many of the hazards and offers good exposure. The operative procedure in such a case is described in detail, and its merits are discussed.

Antiarrhythmic effect of hypertonic sodium bicarbonate and sodium chloride in ouabain-induced arrhythmias.

Ouabain-induced tachyarrhythmias in cats can be abolished by bolus injection of NaHCO3 solution. This effect is consistent, rapid and of short duration. The antiarrhythmic effect appears to be due to high sodium concentration of this solution, as hypertonic NaCl solution with equal concentration of sodium exerts the same effect. Alkalinity and hyper-osmolality cannot account for the antiarrhythmic effect of NaHCO3 as respiratory alkalosis and mannitol solution with equal osmolality did not relieve the arrhythmias. Overdrive suppression is not responsible for this effect as the heart rate slows down during normalization of the cardiac rhythm. It is postulated that high Na+ concentration abolished ouabain-induced arrhythmias by competition with calcium ion in the myocardial cell sarcotubular system thus replacing it. This hypothesis is supported by the known effect of other agents such as sodium-EDTA and magnesium chloride, in digitalis-induced arrhythmias, which exert their antiarrhythmic properties by removal or displacement of calcium in the myocardial cells.