Transcatheter closure of a patent ductus arteriosus in an elderly patient with the Gianturco-Grifka vascular occlusion device.

This paper reports the unusual case of a 76-year-old woman who was discovered to have a hemodynamically significant patent ductus arteriosus following uneventful mitral valve replacement, utilizing cardiopulmonary bypass. The shunt was successfully eliminated using a new transcatheter device, thereby obviating the need for further surgery. The patient did not have calcification within the ductus, making diagnosis prior to surgery more difficult.

Terminating ventricular fibrillation by chest thump.

A 41-year-old man with a surgically closed atrial septal defect presented with anginalike symptoms of 5 years duration. While undergoing coronary arteriorgraphy, the patient sustained ventricular fibrillation which was converted successfully to sinus rhythm by a chest thump. This is the first reported case of such conversion.

Programmed simultaneous biventricular stimulation in man, with special reference to its use in the evaluation of intraventricular reentry.

Programmed stimulation was alternatively performed exclusively from the right ventricular endocardium, exclusively from the left ventricular epicardium and simultaneously from both ventricles in 8 patients who did not have coronary artery disease or bundle branch block. A specially constructed QRS triggered pacemaker, (with a refractory period of 260 msec and an escape interval of 800 msec) connected to the right ventricular and left ventricular electrodes, was used to perform simultaneous biventricular stimulation. The latter had no untoward effects and was not more dangerous than exclusive right ventricular, or exclusive left ventricular, stimulation.

Atypical Wenckebach periodicity simulating Mobitz II AV block.

Eleven patients were studied and a total of 144 Wenckebach cycles in the AV node and 118 Wenckebach cycles in the His-Purkinje system were analysed to determine the incidence of typical and atypical Wenckebach periodicity, with particular emphasis on one variant of atypical Wenckebach that may simulate a Mobitz type II block. This pseudo-Mobitz II pattern was defined as a long Wenckebach cycle in which, at least, the last three beats of the cycle show relatively constant PR intervals (variation of no more than 0.02 s in surface leads and no more than 10 ms in His bundle electrograms) and in which the PR interval immediately following the blocked beat is shorter than the PR interval before the block by 0.

Functional significance of electrocardiographic changes after left ventricular aneurysmectomy.

Electrocardiographic (ECG) changes after left ventricular aneurysmectomy were analyzed in 20 patients, thirteen of whom had additional aorto coronary saphenous vein bypass surgery. ECG changes were correlated with postoperative clinical and hemodynamic results. Out of 14 patients (Group I) who showed hemodynamic and/or clinical improvement, eight had decrease of chronic ST segment elevation that was associated in five with loss of pathologic Q waves.

Mechanical stimulation of the heart: its therapeutic value in tachyarrhythmias.

This report presents the experience obtained with the use of mechanical stimulation of the heart by external ("chest thump") and internal (stimulation via catheter) means in the treatment of tachyarrhythmias. The chest thump was used primarily for termination of ventricular tachyarrhythmias. Endocardial stimulation of the right and left ventricles and right atrium via catheters was used for both ventricular and supraventricular arrhythmias.

Relationship of systemic and intrarenal hemodynamics in cirrhosis.

The relationship between systemic and renal hemodynamics was studied in 20 patients with advanced cirrhosis of the liver. Cardiac output was assessed by an indicator dilution technique, and both mean renal blood flow and intrarenal blood flow distribution were determined by the 133Xe washout method. Ten patients had elevated cardiac outputs (7.

Long-term clinical and hemodynamic studies after ventricular aneurysmectomy and aorta-coronary bypass.

Late clinical and hemodynamic evaluations in 18 patients with ventricular aneurysmectomy and aorta-coronary bypass are presented. Tne patients had significant obstructive lesions in two major vessels (55 per cent), and 6 had extensive three vessel disease (33 per cent). In 13 patients, 21 aorta-coronary saphenous bypass grafts were performed in addition to aneurysmectomy.

Disruption of proximal aortosaphenous vein anastomosis. Late complication of aortocoronary bypass surgery.

A 43-year-old man who had undergone aortocoronary saphenous vein bypass developed disruption of the proximal aorto-saphenous vein anastomosis. Although rare, a mediastinal hematoma secondary to leakage or disruption of an anastomotic site should be considered in patients who develop a mediastinal mass after aortocoronary bypass surgery.

Coronary artery aneurysms: study of the etiology, clinical course and effect on left ventricular function and prognosis.

Coronary artery aneurysms were found in 16 men between 37 and 62 years of age, mean 51 years. Aneurysms were of two types: saccular and fusiform. They involved the right coronary artery in 13 (87 per cent), the circumflex artery in eight (50 per cent) and the left anterior descending artery in five (31 per cent).

Intermittent AV conduction disturbances in patients with AV nodal bypass tracts. Possible mechanisms of unusual variant of tachycardia-bradycardia syndrome.

His bundle recordings were performed in 2 patients in whom AV nodal bypass tracts coexisted with intermittent AV conduction disturbances occurring below the site from which the His bundle deflection was recorded. Case 1 had: (a) tachycardia dependent right bundle-branch block, (b) persistent HV prolongation, and (c) bradycardia dependent AV block. Case 2 showed: (a) intra-atrial conduction delay, (b) tachcardia dependent left bundle-branch block with HV prolongation, (c) bradycardia dependent HV conduction disturbance, (d) tachycardia-bradycardia syndrome of an unusual type; the latter presumably resulted, during atrial flutter, from the alternation of rapid AH conduction through the bypass tract with intermittent (complete) distal His bundle block or bilateral bundle-branch block.

His bundle recordings: their contribution to the understanding of human electrophysiology.

His bundle electrocardiography has increased our understanding of the electrophysiology of the conducting system and has confirmed a number concepts which evolved from analysis of surface electrocardiograms. Electrophysiologic evaluation of conduction disease in the cardiac catheterization laboratory has become an accepted diagnostic procedure in determining the site of atrioventricular and ventriculo-atrial block as well as in the evaluation of patients with pre-excitation resulting from conduction through Kent and James bundles. Recent reports suggest that His bundle electrograms may prove to be of clinical and therapeutic significance in determining the site of re-entry in patients with PSVT as well as in determining the short-term prognosis of patients with acute myocardial infarction complicated by incomplete bundle branch block.

His bundle recordings in diagnosis of impulse formation in Kent and Mahaim tracts.

His bundle electrograms were recorded in 2 patients with ectopic beats arising in accessory atrioventricular tracts. Case 1 had Wolff-Parkinson-White (WPW) type A and a left-sided Kent tract with a short effective refractory period. Though ectopic impulse formation most probably occurred within the Kent tract itself, a vulnerability-related origin in the ventricular muscle close to the distal end of the Kent tract could not be excluded.

Regional refractoriness within the ventricular conduction system. An evaluation of the "gate" hypothesis.

We studied the refractoriness of Purkinje fibers with the intent of localizing critical sites of block of premature impulses. To preserve the ventricular conducting system (VCS) nearly intact in vitro, we used a modification of the Elizari preparation. This was superfused with a physiologic salt solution.

The His-Purkinje electrocardiogram in man: an initial assessment of its uses and limitations.

A methodology is described for noninvasive recording of the electrical activity generated by the His-Purkinje system of man utilizing filtering, high amplification, and signal averaging. A waveform ranging between 1 and 10mu V was observed during the P-R segment. In many individuals, there was temporal overlap between the terminal P wave and the initial portion of the His-Purkinje waveform.