Wide QRS tachycardia refractory to pharmacologic interventions and cardioversion

The case of a 43-year-old man with an idiopathic wide QRS tachycardia resistant to adenosine, lidocaine, procainamide, and multiple electric shocks is described. The tachycardia eventually stopped after a pacing wire was introduced in the right ventricle, inducing a run of rapid ventricular tachycardia. The possible causes of resistance to medications and cardioversion, and alternative treatment modalities are reviewed.

Sleep apnea in heart transplant recipients: type, symptoms, risk factors, and response to nasal continuous positive airway pressure

BACKGROUND

We determined the type, symptoms, and risk factors for sleep apnea in heart transplant recipients and the response to nasal continuous positive airway pressure.

METHODS

A retrospective study on heart transplant recipients with sleep apnea was conducted in a tertiary care medical center with follow-up telephone interviews. Between February 1988 and August 1998, 147 patients underwent orthotopic heart transplantation at our institution. Seventeen patients (11.6%) who were suspected of having sleep apnea underwent polysomnography at a mean interval of 17.5 months after transplantation.

RESULTS

All were diagnosed with sleep apnea: 13 had obstructive sleep apnea and 4 had mixed sleep apnea. Mean age at polysomnography was 50.8 years (range, 24-67 years). The patients presented with snoring (100%), excessive daytime somnolence (65%), witnessed apneas (53%), and morning fatigue (53%). Sixteen (94%) had a mean weight gain of 10.4 kg after transplantation, and 1 patient lost 14.6 kg. In the 11 patients with obstructive sleep apnea who underwent nasal continuous positive airway pressure titration, significant improvements occurred in the apnea-hypopnea index (decreased from 37.6 to 10.4; p = 0.01) and mean arousal index (decreased from 44.5 to 19.4; p = 0.01). Only 2 of the 8 patients with sleep apnea for whom nasal continuous positive airway pressure was recommended continued to use it at the time of telephone follow-up.

CONCLUSIONS

Sleep apnea, especially obstructive sleep apnea, occurs frequently in heart transplant recipients. Obstructive sleep apnea appears to present in the typical manner, and although a positive response to nasal continuous positive airway pressure can be documented by polysomnography, long-term use of nasal continuous positive airway pressure may be low.

Reversible catecholamine-induced cardiomyopathy in a heart transplant candidate without persistent or paroxysmal hypertension

BACKGROUND

Both dilated and hypertrophic cardiomyopathy have been reported in patients with pheochromocytoma, who were almost always hypertensive. The outcome frequently has been fatal, yet cardiac dysfunction can be reversible after medical or surgical therapy for the pheochromocytoma.

METHODS

We report the case of a patient with dilated cardiomyopathy without persistent or paroxysmal hypertension, who was found to have a pheochromocytoma during initial medical evaluation.

RESULTS

The identification and treatment of the pheochromocytoma led to significant improvement in cardiac function and cardiac transplantation was avoided.

CONCLUSIONS

This case illustrates some unusual features in pheochromocytoma-induced cardiomyopathy: (1) absence of persistent or paroxysmal hypertension, (2) initial presentation with acute myocardial infarction and normal coronary arteries, and (3) recurrent episodes of nonsustained ventricular tachycardia.