Eduardo Moreyra

Clinical features of hypertrophic cardiomyopathy in the young.

BACKGROUND We analysed the experience with hypertrophic cardiomyopathy in two paediatric centres to establish the differences from older patients. METHODS Out of 45 young patients seen from 1974 to 1999, we included 38. Criterions for exclusion were secondary forms, or association with severe congenital cardiac disease which could alter the outcome. RESULTS The patients presented at the age of 5.7 years, and were followed for 7.0 years. The 34 patients referred because of a murmur or cardiomegaly were older than the four with heart failure, presenting at 6.2 as opposed to 2.1 years of age, p = 0.08. Of the patients, 29 (76%) had primary cardiomyopathy, while 9 (24%) had secondary forms associated with Noonans and LEOPARD syndromes. Familial tendency was ascertained in 7 patients (18%). The septal thickness in mm/m2 at presentation was greater in patients under 2 years than in older children (29 vs 18, p = 0.02). Obstructive hypertrophic cardiomyopathy was found in 17 patients (45%), with six of these having mild associated congenital cardiac defects. Nine had symptomatic arrhythmias. Overall, treatment was medical in 31, with DDD pacing used in 5, and surgery, radiofrequency ablation, and transplantation in one patient each. Total mortality was 24%, at a rate of 4.3% per year. Four patients died in heart failure and 5 had sudden death. Those in failure were significantly younger (p = 0.01). CONCLUSIONS Hypertrophic cardiomyopathy in the young is characterized by referral for murmur or heart failure; frequent secondary forms; the obstructive variant being as common as the non-obstructive form; a mortality rate similar to that for adults attending tertiary centres; and less frequent familial forms than in older populations.

Mid‐Term Results of Dual‐Chamber Pacing in Children with Hypertrophic Obstructive Cardiomyopathy

Background: Permanent dual‐chambered pacing (DDD) is an alternative to surgical treatment in patients with severe hypertrophic obstructive cardiomyopathy (HOCM) who do not have a satisfactory response to medical treatment. Methods: Five children with severe HOCM still symptomatic despite medical treatment underwent permanent DDD pacing and were followed for 21 ± 9.7 months. Results: All patients improved their functional class. Doppler echocardiographic studies showed an early reduction of the left ventricular outflow tract gradient from 66 ± 40 to 40 ± 20 mmHg (P < 0.05) and to 30 ± 11 mmHg (P < 0.05 and NS for comparison with the baseline and the early post‐DDD pacing gradients, respectively) at mid‐term follow‐up. There was no evidence of left ventricular systolic dysfunction, and the results of left ventricular filling studies ruled out deleterious effects on diastolic function. Doppler echocardiography played a key role in the initial and subsequent assessment of these patients. Conclusions: Permanent DDD pacing is a reasonable alternative to surgery in children with HOCM who are still symptomatic despite medical therapy.

Relationship between electrocardiographic characteristics of left bundle branch block and echocardiographic findings

BACKGROUND Complete left bundle branch block (CLBBB) is an electrocardiographic (ECG) dromotropic disorder seen in patients with various structural heart diseases and sometimes is associated with poor prognosis. Its presence confounds the application of standard ECG criteria for the diagnosis of left ventricular hypertrophy (LVH), myocardial infarction (MI) in the chronic phase, and pathologies that produce changes on ST-T segment. The aim of this investigation was to establish the relationship between CLBBB and cardiac structural abnormalities assessed by echocardiography. METHODS This observational, cross-sectional study included ECG with CLBBB from 101 patients who also had transthoracic echocardiogram (TTE) performed within 6 months. RESULTS The prevalence of structural heart disease on TTE was 90%. No ECG criterion was useful to diagnose LVH since no relationship was observed between 9 different ECG signs and increased left ventricular mass index. QRS duration (p = 0.16) and left axis deviation (p = 0.09) were unrelated to reduced left ventricular ejection fraction (LVEF). Eight ECG signs proposed for the diagnosis of the chronic phase of MI demonstrated similar effectiveness, with high specificity and reduced sensitivity. CONCLUSIONS CLBBB is associated with elevated prevalence of cardiac structural disease and hinders the application of common ECG criteria for the diagnosis of LVH, reduced LVEF, or chronic phase of MI. No ECG finding distinguished patients with structural heart disease from those with normal hearts. Electrocardiographic criteria for the diagnosis of MI in the chronic phase are useful when present, but when absent cannot rule it out.

Embolic Accident Following Heparin Therapy for a Left Ventricular Clot Diagnosed by TEE

There are few data available on the incidence of embolic events inpatients with systemic anticoagulation. We describe a 40‐year‐old woman in congestive heart failure who was shown by transesophageal echocardiography to have an apical thrombus in the left ventricle without concomitant aneurysm. The patient was started on heparin immediately after the diagnosis was established. Twelve hours later she developed an embolic cerebrovascular accident. We believe that heparin dislodged the thrombus as occurs occasionally with thrombolytic agents used in the treatment of acute myocardial infarction.

Use of Phentolamine as Compared to Other Tests in the Clinical Diagnosis of Muscular Subaortic Stenosis

In 32 patients with proven diagnosis of muscular subaortic stenosis, auscultation and phonocardiography were performed in the following positions: supine, supine with the legs passively elevated, stan

Hypertrophic Cardiomyopathy in Infants and Children

The definition and classification of the cardiomyopathies has been traditionally a complex and quite variable subject. In 2006, the American Heart Association issued a scientific statement elaborated by a task force of experts that contemplated the important development of molecular genetics in recent years, to explain the etiology of the diseases of cardiac muscle, or cardiomyopathies, previously considered idiopathic (B.J. Maron et al., 2006a). The document stated that “Cardiomyopathies are an heterogeneous group of myocardial diseases associated with mechanical and/or electrical dysfunction that usually, but not always, exhibit inappropriate ventricular hypertrophy or dilation, and are originated by a variety of causes, frequently genetic. Cardiomyopathies involve just the heart or are part of systemic disorders that often lead to cardiovascular death or heart failure related disability”. Myocardial damage secondary to coronary atherosclerosis, heart valve disease, congenital heart disease, and systemic hypertension, is excluded from this definition. Primary or metastatic cardiac tumors and diseases primarily affecting the endocardium with minimal or absent myocardial damage neither are included. The document also discourages the use of the classical terminologies hypertrophic, dilated, and restrictive cardiomyopathies because they have overlapping features and often mutate from one type to another during the course of the disease. Cardiomyopathies are then classified into 2 groups, primary when there is only heart involvement, and secondary if the heart is affected by systemic diseases with multiorganic involvement. (Table 1) Primary cardiomyopathies are divided into genetic, acquired, and mixed (genetic and acquired).