Left Ventricular Obstructive Lesions Research Articles

Simultaneous presence of atrial arrhythmia and hypocalcemia in dilated cardiomyopathy: A series of two cases

Dilated cardiomyopathy in young children has varied etiological factors. Some cases have correctable causes such as incessant arrhythmia, correctable metabolic abnormality, and left ventricular obstructive lesions. Two 4-month-old infants presented with severe left ventricular dysfunction and ectopic atrial tachycardia. Biochemical profile of the infants showed low ionic and total calcium, elevated serum phosphate, elevated alkaline phosphatase, and elevated serum lactate. The parathyroid hormone was elevated and 25-hydroxyvitamin D3 was reduced. The patients were treated with beta-blocker, calcium, and Vitamin D supplementation, along with antifailure therapy. The tachycardia resolved over a 12-h period and calcium normalized in the next few days. The left ventricular function returned to normal over a 5–16-month period. In 6–8 years of follow-up, patients were in sinus rhythm doing very well with normal cardiac function with normal calcium-related biochemical parameters. The presence of incessant atrial arrhythmia in a case of hypocalcemic cardiomyopathy is rare and can have link with hypocalcemia-induced electrical changes in the cardiomyocyte in selected cases. Thorough and protocol-based treatment approach helps in correct diagnosis and treatment. Further study and molecular research can shed more light on the complex interaction of hypocalcemia and arrhythmia.

Three‐Dimensional Echocardiographic Evaluation of a Patient with Double‐Orifice Mitral Valve, Bicuspid Aortic Valve, and Coarctation of Aorta

A 16-year-old male patient was diagnosed with bicuspid aortic valve and coarctation of aorta, and had a history of a subclavian patch plasty operation at 1 year of age. In addition, we detected double-orifice mitral valve (DOMV) at a routine evaluation and demonstrated by both two-dimensional and three-dimensional (3D) echocardiographic examinations. DOMV should be kept in mind in cases with left ventricular obstructive lesions and 3D echocardiography may provide a more detailed assessment of mitral valve and subvalvular apparatus.

Cardiac abnormalities in birth asphyxia.

Cardiac abnormalities in birth asphyxia were first recognised in the 1970s. These include (i) transient tricuspid regurgitation which is the commonest cause of a systolic murmur in a newborn and tends to disappear without any treatment unless it is associated with transient myocardial ischemia or primary pulmonary hypertension of the newborn (ii) transient mitral regurgitation which is much less common and is often a part of transient myocardial ischemia, at times with reduced left ventricular function and, therefore, requires treatment in the form of inotropic and ventilatory support (iii) transient myocardial ischemia (TMI) of the newborn. This should be suspected in any baby with asphyxia, respiratory distress and poor pulses, especially if a murmur is audible. It is of five types (A to E) according to Rowe's classification. Type B is the most severe with respiratory distress, congestive heart failure and shock. Echocardiography helps to rule out critical left ventricular obstructive lesions like hypoplastic left heart syndrome or critical aortic stenosis. ECG is very important for diagnosis of TMI, and may show changes ranging from T wave inversion in one lead to a classical segmental infarction pattern with abnormal q waves. CPK-MB may rise and echocardiogram shows impaired left ventricular function, mitral and/or tricuspid regurgitation, and at times, wall motion abnormalities of left ventricle. Ejection fraction is often depressed and is a useful marker of severity and prognosis. Treatment includes fluid restriction, inotropic support, diuretics and ventilatory resistance if required (v) persistent pulmonary hypertension of the newborn (PPHN). Persistent hypoxia sometimes results in persistence of constricted fetal pulmonary vascular bed causing pulmonary arterial hypertension with consequent right to left shunt across patent ductus arteriosus and foramen ovale. This causes respiratory tension and right ventricular failure with systolic murmur of tricuspid, and at times, mitral regurgitation. Treatment consists of oxygen and general care for mild cases, ventilatory support, ECMO and nitric oxide for severe cases. Cardiac abnormalities in asphyxiated neonates are often underdiagnosed and require a high index of suspicion. ECG and Echo help in early recognition and hence better management of these cases.

Endogenous dilator prostaglandins in congenital heart disease.

Maintaining patency of the ductus arteriosus pending surgical intervention can be critical to the survival of the neonate with ductal dependent congenital heart disease. Spontaneously delayed ductal closure has been observed clinically and experimentally in newborns with critical pulmonic stenosis. Infants with ductal dependent congenital heart lesions were therefore studied to ascertain whether there was an endogenous increase in dilator prostaglandins prolonging ductal patency. Six neonates with cyanotic lesions (group 1) and six with left ventricular obstructive lesions (group 2) were studied. Circulating PGE2 was not increased in either group. The levels of plasma 6 keto PGF1 alpha, a stable hydrolysis product of prostacyclin, were found to be elevated, but only in the cyanotic group (3143 +/- 1844 vs 404 +/- 250 pg/ml; p less than 0.05; normal less than 500 pg/ml). As expected, PaO2's were also different (36 +/- 15 vs 72 +/- 34 mmHg; p less than 0.05). It is speculated, therefore, that increased synthesis and/or release of prostacyclin, possibly mediated by the hypoxia of the cyanotic ductal dependent lesion, contributes to persistent patency of the ductus arteriosus.

Symptomatic atrial septal defect in infancy.

Atrial septal defect of the ostium secundum variety (ASD) is uncommonly diagnosed in infancy and rarely results in congestive heart failure (CHF). Eleven patients with uncomplicated ASD who developed CHF between 6 days and 13 months of age are presented. The diagnosis of ASD was documented by cardiac catheterization in all 11 patients. Left-to-right shunt ranged from 52 to 80%. Right ventricular pressure was near systemic levels in two patients and at least somewhat elevated in the other nine. Total pulmonary resistance (TPR) was within normal limits in all 11. No left ventricular obstructive lesions were found. Although one patient had unusual thickening of the left ventricular myocardium, and the left ventricular cavity was enlarged in two other cases, no specific abnormality in left or right ventricular function could be defined. Spontaneous closure of the ASD did not occur in any of our patients. Since spontaneous closure even of a large ASD can occur, however, it seems advisable to defer elective surgical closure until after 2 years of age if successful medical management can be achieved. In those patients in whom early surgery is not necessary, the clinical course usually becomes that of a typical ASD by age 2 years.

Symptomatic atrial septal defect in infancy

Atrial septal defect of the ostium secundum variety (ASD) is uncommonly diagnosed in infancy and rarely results in congestive heart failure (CHF). Eleven patients with uncomplicated ASD who developed CHF between 6 days and 13 months of age are presented. The diagnosis of ASD was documented by cardiac catheterization in all 11 patients. Left-to-right shunt ranged from 52 to 80%. Right ventricular pressure was near systemic levels in two patients and at least somewhat elevated in the other nine. Total pulmonary resistance (TPR) was within normal limits in all 11. No left ventricular obstructive lesions were found. Although one patient had unusual thickening of the left ventricular myocardium, and the left ventricular cavity was enlarged in two other cases, no specific abnormality in left or right ventricular function could be defined. Spontaneous closure of the ASD did not occur in any of our patients. Since spontaneous closure even of a large ASD can occur, however, it seems advisable to defer elective sur...