11/907. Subaortic obstruction after the use of an intracardiac baffle to tunnel the left ventricle to the aorta. Postoperative hemodynamic studies in five patients document subaortic obstruction after surgical repair utilizing an intracardiac baffle to establish continuity between the left ventricle and the aorta. Four of the patients had a Rastelli procedure for D-transposition of the great arteries with a ventricular septal defect and pulmonary stenosis; one patient had repair of double outlet right ventricle with a ventricular septal defect and pulmonary stenosis. The left ventricular outflow was shown to be a long narrow tunnel by angiography in four of five patients and by echocardiography in one patient. Resting aortic peak systolic pressure gradient ranged from 10 to 42 mm Hg (mean 24). The obstruction was localized to the proximal end of the left ventricule to aorta tunnel (i.e., at the site of ventricular septal defect) in five patients. One patient with a gradient of 42 mm Hg has angina and decreased exercise tolerance. Subaortic obstruction is a newly described sequelae after the Rastelli procedure for transposition or repair of double outlet right ventricle. The obstruction may be hemodynamically significant and should be searched for at postoperative cardiac catheterization. ( info) |
12/907. Maternally inherited cardiomyopathy: clinical and molecular characterization of a large kindred harboring the A4300G point mutation in mitochondrial deoxyribonucleic acid. OBJECTIVES: The purpose of this study was to describe the clinical and molecular features of a large family with maternally inherited cardiomyopathy (MICM). BACKGROUND: Recently, several mitochondrial deoxyribonucleic acid (mtDNA) point mutations have been associated with MICM. However, the distinctive clinical and morphologic features of MICM are not fully appreciated. This is partially due to the small size of the reported pedigrees, often lacking detailed clinical and laboratory information. methods: Clinical and genetic analysis of the family was carried out. RESULTS: echocardiography showed mostly symmetrical hypertrophic cardiomyopathy in 10 family members. The illness had an unfavorable course. Progressive heart failure occurred in three subjects, who eventually died; one individual underwent heart transplantation. Electrocardiographic or echocardiographic signs of cardiac hypertrophy in the absence of significant clinical complaints were observed in five subjects. neurologic examination was normal. The mutation was detected in blood from all available subjects. Abundance of mutated molecules ranged between 13% and 100% of total mtDNA genomes. The severity of the disease could not be foreseen by the proportion of mutation in blood. CONCLUSIONS: This report contributes a better description of the clinical aspects of MICM and provides important clues to distinguish it from hypertrophic cardiomyopathy. We suggest that mtDNA mutations, particularly in the transfer ribonucleic acid for isoleucin, should be systematically searched in patients with MICM. The identification of an underlying maternally inherited mitochondrial dna defect in familial cases of cardiomyopathy may considerably influence the management and genetic counseling of affected patients. ( info) |
13/907. Persistent ST segment elevation: a new ECG finding in hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy is a primary disease of myocardium resulting in myocardial hypertrophy without any inciting pressure or volume overload. The typical triad of symptoms includes exertional angina, syncope, and shortness of breath. Sudden cardiac death, the most dreadful complication of this disorder, can be the first manifestation of the disease and is more common in young patients. Elderly patients, on the other hand, may have a relatively benign course with normal or near-normal life span. The electrocardiogram (ECG) and echocardiography are the two most useful measures to diagnose hypertrophic cardiomyopathy. The electrocardiographic features of hypertrophic cardiomyopathy are numerous, including ST segment elevation that may simulate other ST segment elevation syndromes, including acute myocardial infarction, variant angina pectoria, acute pericarditis, bundle branch blocks, ventricular paced rhythm, dyskinetic ventricular segment, ventricular aneurysm, left ventricular hypertrophy, wolff-parkinson-white syndrome, and early repolarization syndrome. This report describes a case of an asymptomatic patient who presented with ST segment elevation of acute injury type and, therefore, was admitted to rule out silent myocardial infarction. myocardial infarction was ruled out by cardiac enzyme levels, but ST segment elevation remained persistent in all of the subsequent ECGs. echocardiography was performed, which clearly showed hypertrophic cardiomyopathy with left ventricular outflow tract obstruction and a high intracavity pressure gradient. Subsequently, retrieval of old ECGs showed a similar type of ST segment elevation in the patient's previous ECGs. ( info) |
14/907. Hypertrophic cardiomyopathy in Friedreich's ataxia. The cardiac findings in two sibs with Friedreich's ataxia are described. The clinical signs were suggestive of hypertrophic obstructive cardiomyopathy. During left heart catheterization a systolic pressure gradient across the left ventricular outflow tract could be provoked by an infusion of isoprenaline. Left ventricular angiocardiograms and echocardiograms showed gross thickening of the interventricular septum. In one patient a systolic anterior movement of the anterior leaflet of the mitral valve was seen. The importance of serial echocardiographic examination for patients with Friedreich's ataxia is emphasized. ( info) |
15/907. Pre- and postoperative echocardiographic features of discrete subaortic stenosis. In two patients with discrete membranous subaortic stenosis, partial early systolic closure of the aortic valve was noted on the preoperative record. Postoperatively, this abnormality was found to be less pronounced. Narrowing of the left ventricular outflow tract was seen in the preoperative tracing in each patient. Echocardiograms taken after resection of the subaortic membrane showed widening of the left ventricular outflow tract as compared with the preoperative tracing. Thus, echocardiography may be of value in distinguishing between discrete subaortic stenosis and other forms of left ventricular outflow tract obstruction. ( info) |
16/907. Apical hypokinesis in a patient with hypertrophic cardiomyopathy and myocardial bridging: reversal with beta-blockade--a case report. A 42-year-old man presented with effort angina pectoris of 20 minutes' duration. Hypertrophic obstructive cardiomyopathy, severe myocardial bridging involving the midleft anterior descending coronary artery, and apical hypokinesis were identified. Regional wall motion normalized following the initiation of beta blockade. ( info) |
17/907. An interesting case of infant sudden death: severe hypertrophic cardiomyopathy in Pompe's disease. glycogen storage disease type ii (Pompe's disease) is a rare inherited metabolic disorder, which often leads to infantile death from severe cardiomyopathy. This case of sudden death illustrates the features of the cardiac findings in the disorder, resulting from massive lysosomal accumulation of glycogen in the heart and other tissues. Pompe's disease should be considered in cases of unexplained infantile cardiomyopathy. ( info) |
18/907. Electrophysiologic characteristics of accessory atrioventricular connections in an inherited form of wolff-parkinson-white syndrome. INTRODUCTION: A familial form of wolff-parkinson-white syndrome (WPW) occurs in association with hypertrophic cardiomyopathy and intraventricular conduction abnormalities. This syndrome, demonstrating autosomal dominant inheritance and segregating with a high degree of penetrance but variable expressivity, has been genetically linked to chromosome 7q3. The purpose of this study is to detail the electrophysiologic characteristics of accessory atrioventricular connections (AC) in four members of a kindred with this syndrome. methods AND RESULTS: We clinically evaluated 32 members of a single kindred and identified 20 individuals with ventricular preexcitation, abnormal intraventricular conduction including complete AV block and/or ventricular hypertrophy. genetic linkage analysis mapped the disease gene in this kindred to the chromosome 7q3 locus (maximum logarithm of the odds score = 6.88, theta = 0); recombination events in affected individuals reduced the genetic interval from 7 centimorgans (cM) to 5 cM. Electrophysiologic study of four individuals with preexcitation, identified seven AC (1 right sided, 3 septal, and 3 left sided). All four individuals had inducible orthodromic tachycardia; while three had multiple AC. Bidirectional conduction was demonstrated in 6 of 7 AC. Successful ablation was accomplished in 5 of 7 AC. CONCLUSION: The electrophysiologic characteristics and location of AC in family members having this complex cardiac phenotype are similar to those seen in individuals with isolated WPW. Identification of WPW in more than one family member should prompt clinical evaluation of relatives for additional findings of ventricular hypertrophy or conduction abnormalities. ( info) |
19/907. Transient hypertrophic cardiomyopathy in the newborn following multiple doses of antenatal corticosteroids. Postnatal exposure to steroids has been associated with hypertrophic cardiomyopathy (HCM) in the newborn. Such an effect has not been described in infants born to mothers who received antenatal steroids. We report three newborns whose mothers were treated with betamethasone prenatally in different doses, duration of time, and who developed various degrees of HCM diagnosed by echocardiography. There was no maternal evidence of diabetes except for one infant whose mother had a normal fasting and post-prandial blood glucose prior to steroid therapy, but an abnormal one hour postprandial glucose after 8 weeks of betamethasone therapy, with a normal HbA1 C level. There was no family history of HCM, no history of maternal intake of other relevant medications, and no hypertension in all three newborns. Follow-up echocardiography revealed complete resolution of the HCM changes in all infants. We suggest that repeated antenatal maternal steroid intake may cause changes of HCM in the newborn. These changes appear to be dose- and duration-related and are mostly reversible. Further prospective controlled studies to evaluate these observations and to investigate potential mechanisms are warranted. ( info) |
20/907. Infantile hypertrophic cardiomyopathy of glycogenosis type IX: isolated cardiac phosphorylase kinase deficiency. Glycogen storage disease confined to the heart due to cardiac phosphorylase kinase deficiency causes a fatal infantile cardiomyopathy. cardiomegaly can be detected in utero and is progressive. Electrocardiographic and echocardiographic findings are characteristic but not specific; these include large QRS complexes, short PR interval, and a hypertrophic nonobstructive pattern. Conclusive diagnosis requires biochemical analysis of myocardium, which may not be possible premortem due to the amount of tissue required. Pathologic examination of a standard cardiac biopsy can provide a presumptive diagnosis. There is no current treatment except a heart transplant. Infants succumb to heart failure and/or respiratory compromise due to pulmonary compression. This is a rare entity; only three cases have been reported to our knowledge. We report two additional cases. ( info) |