No abstract

In certain batches of a manufacturer's pacemakers, inadequate insulation of the battery cell feed-through mechanism led to internal short-circuiting and premature battery depletion. We describe the impact of the consequent reduction in service life and recommended close supervision of these generators on the follow-up clinics and inpatient workload at a large pacing center. One-hundred and ninety patients had Cordis Gamma series pacemakers implanted between September 1981 and July 1985; 135 have had to undergo premature generator replacement. Eleven of these pacemakers had developed early depletion of rate and 12 no-output failure. Within 3 months of their generator change, 12 patients developed wound sepsis, three of them requiring further system replacement. We calculate that at least 540 extra outpatient appointments, 400 in-hospital patient days and 12 full working days in one of our catheterization laboratories were required to deal with the problems. The pacemaker industry, as well as doctors and technicians involved in pacemaker purchase and implantation, should be aware of the consequences of a major recall not only on workload but also on patient morbidity and anxiety.

SUMMARY Primary pericardial mesothelioma is an extremely rare tumour. This case illustrates the typical late presentation with symptoms and signs of constrictive pericarditis. An unusual feature was complete encasement of the heart by tumour. No satisfactory treatment is available.Case report A 69 year old retired seaman gave a two month history of progressively worsening breathlessness and central chest discomfort on effort. There was associated weight loss, anorexia, night sweats, and pronounced peripheral oedema. Symptoms were partly relieved by diuretics and vasodilators.Previous illnesses included longstanding, but well controlled, hypertension (treated with atenolol and hydralazine) and resection of an enlarged prostate two years before presentation, in which histological examination showed foci of well differentiated prostatic adenocarcinoma.On examination he was unwell, slightly jaundiced, and dyspnoeic at rest. The pulse was regular and of small volume, and the blood pressure was 90/60 mm Hg. The jugular venous pulse was elevated to the angle of the jaw, with sharp "y" descent and there was pitting oedema up to the knees. The cardiac apex was impalpable and the heart sounds quiet without added sounds or murmurs. The lungs were moderately congested with a small right pleural effusion.A chest radiograph showed cardiac enlargement (cardiothoracic ratio 58%), pulmonary venous con- At thoractomy the heart was found to be surrounded by thick white tumour masses, which had spread to the adjacent mediastinal nodes and pleura. Resection was impossible and the patient died several hours after return from the operating theatre.At postmortem the whole heart was found to be encased by tumour, with pericardium adherent to the epicardium forming a continuous band of white tissue 1 cm thick (fig 1). Several nodules of tumour surrounded the great vessels and the heart plus tumour weighed over 1 kg. Numerous small pleural nodules of tumour were present, and none was 54

Summary: Right ventricular overdrive pacing is an effective method for termination of ventricular tachycardia. This may be due to alteration in conduction rate, conduction pathways, or refractory periods of myocardial tissue. The procedure can be facilitated by antiarrhythmic drugs which increase tachycardia cycle length. Sotalol possesses beta-blocking action, has been shown to increase duration of action potentials and refractory periods throughout myocardial tissue and accessory pathways, and can suppress and prevent recurrent malignant ventricular arrhythmias. We describe two cases with ventricular tachycardia which were terminated transiently by cardioversion, but were resistant to various antiarrhythmic drugs. Right ventricular overdrive pacing was used in both cases, but was only effective after the administration of intravenous sotalol. We conclude that the unique properties of sotalol may make it especially effective in this context. Caution is required because of the hypotensive and negative inotropic actions of beta blockers, and possible acceleration of ventricular tachycardia by overdrive pacing.

No abstract