Luis Maria Amuchastegui

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.

Atrial Mechanical Function Before and After Electrical or Amiodarone Cardioversion in Atrial Fibrillation: Assessment by Transesophageal Echocardiography and Pulsed Doppler.

In some patients with atrial fibrillation (AF), it has been suggested that left atrial mechanical dysfunction can develop after successful electrical cardioversion, justifying postcardioversion anticoagulant treatment. The purpose of this study was to investigate differences in left atrial appendage peak flow velocities and the incidence of left atrial spontaneous echo contrast in patients with AF before and after electrical cardioversion or intravenous amiodarone, studied using transesophageal echocardiography (TEE) and pulsed Doppler. We performed a control TEE in 7 patients in the electrical group and 6 in the amiodarone group, with no significant clinical differences between both groups. A second TEE was performed immediately in the 7 patients with successful electrical cardioversion. The peak flow velocities in the appendage before and after the procedure were: filling 43.3 ± 22 vs 27.7 ± 28 cm/sec (P = 0.01) and emptying 35.5 ± 22 vs 23.6 ± 17 cm/sec (P = 0.01), respectively. The spontaneous echo contrast increased in 4 of the 7 patients. In 4 patients of the amiodarone group, the peak flow velocities in the appendage during AF and within the first 24 hours after restoration of sinus rhythm were: filling 37.4 ± 12 vs 37.8 ± 18 cm/sec and emptying 36.4 ± 18 vs 35.9 ± 18 cm/sec, respectively (P = NS). There was no change in spontaneous echo contrast. In conclusion, patients with AF reverted to sinus rhythm using amiodarone did not show changes in left atrial mechanical function; however, patients with electrical cardioversion showed mechanical dysfunction. Further investigations on the effects of amiodarone and other drugs on the mechanical function of the atria are needed to determine if patients reverted pharmacologically require antico‐agulation post reversion.

Right Ventricular Outflow Tract Tumor Mimicking a Thrombus in the Main Pulmonary Artery

Primary sarcomas of the pulmonary artery and right ‘ventricle are rare, and their presentation is unusual in clinical practice; therefore, their diagnosis is often missed or delayed. The progression of the obstruction from the outflow tract of the right ventricle to the pulmonary artery resembles massive pulmonary embolism. We present a case of one of these tumors which mimicked transesophageal echocardiography (TEE), a massive pulmonary embolism. We conclude that TEE represents a non‐invasive method of diagnosis and evaluation when the suspicion is massive pulmonary thromboembolism or a heart tumor.

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