Faculty Bibliography

The presence of a patent foramen ovale allows direct recording of a left atrial (LA) electrogram. Three patients are reported in whom simultaneous high right atrial (HRA), coronary sinus (CS), and direct LA electrograms were obtained. In two patients with normal surface ECG P waves the direct LA lead depolarized before the CS or low RA. The HRA to LRA and HRA to CS conduction times were similar to those reported previously. In a patient with a prolonged surface ECG P wave, the direct LA electrogram occurred late and after low RA depolarization. Recording LA electrograms through a patent foramen ovale is a useful technique, and these defects should be sought in all patients undergoing electrophysiological study

A 30-year-old man with a history of a murmur since childhood had progressive ascites for 2 years. The patient was found to have severe stenoses of the pulmonic and tricuspid valves with a well-developed right ventricle. Impressive clinical improvement occurred after pulmonic valvotomy, infundibulectomy, and replacement of the stenotic tricuspid valve with a porcine xenograft. The clinical, echocardiographic, hemodynamic, surgical, and pathological features are presented

A case is presented in which first-degree block in all three fascicles of the intraventricular conduction system results in a QRS complex with no specific features of fascicular block. During spontaneous sinus arrhythmia the typical features of RBBB and LAH appear at the longest sinus cycles. This is associated with shortened P-R and H-Q intervals. During shorter sinus cycles, near equalization of delay in each fascicle is associated with delay in His-Purkinje conduction but loss of the typical features of bifascicular block as the ventricular myocardium becomes activated more synchronously. Documentation of the changing patterns of ventricular activation is provided by His bundle electrocardiography

The role of circulatory congestion in the cardiorespiratory dysfunction of massive obesity was investigated in 18 patients. They were hypervolemic and had increased cardiac outputs proportionate to their weight. The average resting left ventricular filling pressure was within the upper limits of normal, but it increased to abnormally high levels with increased venous return of passive leg raising, and further during exercise. The elevations in pressure were associated with high resting central blood volumes which increased significantly with exertion. These findings are consistent with reduced distensibility of the central circulation in these congested patients. Weight reduction was accompanied by a decrease in central blood volumes and restoration of a normal left ventricular response in three of four patients and a return toward normal in one. The improvement in ventricular function with relief of edema and dyspnea. In 14 patients with normal or only minimal alveolar hypoventilation, there were no significant transpulmonary diastolic pressure gradients despite a marked increase in left ventricular end-diastolic pressures. One patient, after regaining weight, subsequently had an abnormal gas exchange and an increased pulmonary vascular resistance. He and two others with severe alveolar hypoventilation demonstrated cor pulmonale on a background of left ventricular dysfunction and congestion of the circulation. Two other patients, the least obese of the group, had hypoventilation and cor pulmonale with normal left ventricular pressures. Hypervolemia and a hyperdynamic state are common features of the obese patients. High cardiac output is maintained despite marked circulatory congestion which may result in generalized anasarca and increased ventricular filling pressures. This clinical syndrome may be present in obese patients without intrinsic heart disease and may be reversible with weight reduction. The central circulatory congestion may contribute to the development of the alveolar hypoventilation syndrome in certain obese patients