Early failures of permanently implanted transvenous pacemaker systems: spontaneous recovery of sensing function in three of twelve cases.

An analysis of 12 early pacemaker failures in a series of 128 transvenous implants is reported. Spontaneous recovery, maintained during long-term follow-up of 3 patients with isolated transient sensing failure, suggested the possibility of a transient loss of sensing voltage amplitude, or slew rate (dv/dt), or both. Conservative management is frequently indicated in these cases. In 62 patients in whom a "tined" lead was used, there were no early pacemaker failures.

Two-dimensional echocardiographic findings in right-sided infective endocarditis.

M-mode and two-dimensional echocardiograms were recorded in 12 narcotic addicts who had right-sided infective endocarditis. The two-dimensional echocardiogram showed vegetations in 10 patients (nine tricuspid and one pulmonic), while the M-mode echocardiogram was positive in six (five tricuspid and one pulmonic). The use of multiple transducer positions resulted in better visualization of the valves and appeared to be an important reason for the large number of positive two-dimensional echocardiograms. Echocardiographic findings were also available after completion of antibiotic therapy in seven of 10 patients. Of these seven patients, the vegetation appeared unchanged in three, diminished in size in three and was no longer visualized in one. No patient required valve replacement. Two-dimensional echocardiography using a wide-angle sector scanner appears to offer distinct advantages over the standard M-mode technique in evaluating patients with right-sided infective endocarditis.

The genesis of the diastolic murmur of complete heart block. Phono-echocardiographic observations.

A 72-year-old man with calcific aortic stenosis and complete heart block was noted to have an intermittent diastolic murmur. Using combined echocardiography and phonocardiography, it was demonstrated that the murmur occurred while the mitral valve was closing. This suggested that antegrade flow across a closing mitral orifice is of etiologic importance in the production of the murmur. Atrial sounds were also recorded and probably have a similar etiology. It is postulated that reduced ventricular compliance resulting in a more rapid rate of mitral valve closure was of etiologic importance in the genesis of the murmur.

Pericardial effusion diagnosed by echocardiography. Clinical and electrocardiographic findings in 171 patients.

Clinical and electrocardiographic findings in 171 patients with pericardial effusion diagnosed by echocardiographic studies were reviewed. In 70 patients the effusion was unsuspected. There were 87 small, 50 moderate, and 31 large effusions. Cardiac tamponade was present in three patients. Congestive heart failure was the most common cause of pericardial effusion and occurred in 37 patients. Other frequently noted conditions included cardiac disease without congestive heart failure, neoplasms, acute nonspecific pericarditis, renal failure, and acute myocardial infarction. A pericardial friction rub was present in 23 patients, two-thirds of whom had moderate or large effusions. Atrial arrhythmias were common. Low voltage occurred in 31 of 136 patients and was more common with large effusions. The ability to distinguish between a small effusion and the quantity of pericardial fluid present normally is a problem requiring further clarification.