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Biomedical subjects

L Gould

Publications and source records attributed to L Gould.

At least 145 records · Page 8Linked to original sources
PubMed1977

His bundle electrograms in 51 patients requiring permanent transvenous pacemakers.

Fifty-one patients required the implantation of a Cordis Omnis-Stanicor permanent pacemaker. His bundle electrograms studies, which included right atrial pacing and sinoatrial (SA) node postsuppression recovery times, were performed prior to the implantations. Pacing and sensing thresholds were obtained in all patients. Syncope or episodes of dizziness were the presenting symptoms in virtually every patient. Twenty-eight of the 51 patients had the sick sinus syndrome. Only nine patients were in complete heart block, and an additional nine were in second-degree heart block. The His bundle electrogram technique was not particularly helpful in selecting the potential pacemaker candidate. The symptomatic patient with second- or third-degree heart block requires a pacemaker. In the sick sinus syndrome, the His bundle electrogram was a disappointing tool in detecting abnormalities. In chronic bundle branch block, the His bundle electrogram appears to play a major role. A prolonged H-V interval in a symptomatic patient, in whom a specific noncardiac cause cannot be identified, signifies that a pacemaker is required.

Adult↗
PubMed1976

The effect of nitroglycerin on atrioventricular conduction in man.

His bundle electrograms were performed on 10 patients with organic heart disease. Six patients had had a recent myocardial infarction. Recordings were made at various rates utilizing right atrial pacing. Nitroglycerin, 1/150 gr, was administered to all 10 subjects, and the P-A, A-H, H-Q and H-S intervals were determined before, and immediately after the disappearance of the sublingually administered nitroglycerin. A significant decrease in the A-H interval occurred with negligible effects on the P-A, H-Q and H-S intervals. At the atrial pacing rate of 100/min, the average A-H interval fell from the control value of 152 msec to 129 msec after the administration of nitroglycerin (p less than 0.02); at the pacing rate of 130/min, the A-H interval decreased from 194 to 133 msec (p less 0.05). Second degree heart block occurred at higher pacing rates in six patients after nitroglycerin administration as compared to the control value. The average postsuppression sinoatrial recovery time control value of 1,083 msec decreased to 906 msec after nitroglycerin administration (p less than 0.01). These findings demonstrate that nitroglycerin can improve conduction through the A-V node.

Adult↗
PubMed1976

Phentolamine.

The clinical uses of phentolamine have widened since its introduction as an anti-hypertensive agent. The vasodilating action of the drug as well as its postive inotropic effects have led to its use in treating congestive heart failure. Recently, phentolamine has been use by several groups to improve left ventricular function in acute myocardial infarction. There appears to be great promise for the use of phentolamine in this clinical setting. The drug given intravenously or orally can suppress ventricular premature beats and supraventricular premature beats. However, the experience of phentolamine as an antiarrhythmic agent is still limited. Similarly, the relief of angina pectoris by phentolamine requires confirmation by additional clinical studies. Phentolamine can be used as a provocative test in idiopathic hypertrophic subaortic stenosis. Since it does not produce cardiac arrhythmias, it may be safer than isoproterenol. The comparative effectiveness of phentolamine and isoproterenol in diagnosing I.H.S.S. is unknown. Phentolamine has been advocated for several years as a beneficial agent for the treatment of shock. The experience is still limited to a few groups who have reported favorable results. Phentolamine has been used as a bronchodilator and a pulmonary artery dilator. The preliminary reports appear favorable. However, continused investigation is warranted. A sensitive measurement of the blood levels of phentolamine is not available. When this is accomplished, further insight into the metabolism of this drug will be forthcoming.

Angina Pectoris↗
PubMed1976

Hemodynamic effects of steroids in cardiac disease.

The hemodynamic effects of intravenous methylprednisolone were documented by right heart catheterization in seven patients with an acute uncomplicated transmural myocardial infarction 1 to 9 days after the onset of symptoms. Intracardiac pressures, brachial artery pressure, and cardiac output were determined before and 1 hour after the termination of the methylprednisolone infusion. Two grams of methylprednisolone were infused over a 20 minute period. The brachial pressure rose from a mean of 82 to 90 mm. Hq (N.S.). The brachial artery mean pressure fell in the one patient with a 1-day-old infarction, and it rose in the six patients with an older infarction, from 83 to 94 mm. Hg (p less than 0.01). As the brachial artery pressure rose in one patient, chest pain and marked ST-segment elevation occurred which were relieved by nitroglycerin. This experience promoted us to terminate the steroid study. There was a nonsignificant increase in the cardiac index and wedge pressure. The raise in the brachial artery pressure with an infarction older than 1 day was an unexpected finding, since steroids are presumed to be vasodilating agents.

Adult↗
PubMed1976

Effect of cold isotonic glucose infusion on A-V nodal conduction.

His bundle electrograms were performed in eight patients with organic heart disease. Recordings were made at various rates utilizing right atrial pacing. A solution of 100 cc of iced cold 5% glucose and water was infused through a cardiac catheter placed at the level of the tricuspid valve. The P-A, A-H, H-Q and H-S intervals were determined before and immediately after the cold water infusion. A significant prolongation of the A-H interval occurred with negligible effects on the P-A, H-Q and H-S intervals. At the atrial pacing rate of 100/min the average A-H interval increased from the control value of 116 to 125 msec after the infusion (P less than 0.02); at the pacing rate of 140/min, the A-H interval increased from 147 to 158 msec (P less than 0.01). This represents an impairment in conduction through the atrioventricular node.

Action Potentials↗
PubMed1976

Recurrent tachycardias due to an accessory pathway.

A 48 year old female presented with a long history of palpitations and syncopal episodes. His bundle electrogram studies were performed in order to evaluate the conduction system. The electrocardiogram (ECG) revealed normal PR and QRS intervals, while the unpaced His electrogram was normal. With atrial pacing rates of 110 to 180 beats/min, the AH and HV intervals remained essentially unchanged. This signifies that there was an accessory conduction pathway which bypassed the AV node. Thus, pre-excitation can not be eliminated as a diagnostic possibility even if the ECG is normal.

Electrocardiography↗
PubMed1976

Cardiac manifestations of ochronosis.

A 68-year-old woman with ochronosis was admitted with congestive heart failure. A typical ejection murmur of aortic stenosis was ausculated and was documented on a phonocardiogram. The patient subsequently died, and at autopsy extensive deposition of ochronotic pigment was found on the aortic valve. This valve had no other anatomic abnormalities. Thus ochronosis should be considered in the differential diagnosis of aortic stenosis.

Aged↗
PubMed1975

The effect of pharmacologic doses of steroids on atrioventricular conduction in man.

His bundle electrograms were performed in ten patients with organic heart disease. Recordings were made at various rates using right atrial pacing. Two grams of methylprednisolone were infused intravenously over a 20-minute period. The PI-A, A-H, H-Q, and H-S intervals were obtained before and up to 1 hour after the infusion of the steroid. The maximum effect was seen at 1 hour. All patients showed a significant prolongation in the A-H interval with negligible effects on other intervals. At the atrial pacing rate of 120 beats/minute, the average A-H interval increased from control of 119 milliseconds to 159 milliseconds after steroids (P smaller than 0.01). Second-degree heart block occurred at lower pacing rates after steroids in six patients as compared with the control state. The postsuppressive sinoatrial node recovery time was increased in seven cases after steroid infusion. Pharmacologic doses of steroids can impair conduction through the atrioventricular node.

Adult↗
PubMed1975

Prognosis of left anterior hemiblock in acute myocardial infarction.

Four of 32 patients with left anterior hemiblock and an acute anterior wall myocardial infarction died. Left anterior hemiblock was present on admission in 24 patients, and subsequently appeared in 8. Of the 28 survivors, 21 are still alive an average of 2.8 years after the acute myocardial infarction.

Acute Disease↗
PubMed1975

Effects of phentolamine on coronary blood flow in patients with recent myocardial infarction.

The myocardial clearance of rubidium may be obtained by praecordial counting after intravenous injection of Rb-minus 86 Cl. Eight patients with recent myocardial infarction had this determination performed before and after the infusion of 10 mg phentolamine at a rate of 0.3 mg/minute. The average predrug myocardial clearance of Rb was 89.3 plus or minus 29.9 ml/min per 100 g myocardium. After phentolamine, the average myocardial clearance rose to 117.3 plus or minus 33.3 ml/min per 100 g myocardium (P LESS THAN 0.01). An explanation for this findings is presented as well as its possible clinical applications.

Adult↗
PubMed1975

The effects of chronic ventricular pacing on the human conduction system.

Six cardiac patients had His bundle electrograms obtained prior to ventricular pacing. Hours to days after constant pacing, repeat His bundle electrograms were obtained. The H-Q interval increased after pacing in 5 of the 6 patients. The average H-Q interval of 55.8 msec increased to the post pacing value of 67.5 msec (p smaller 0.02). Thus ventricular pacing can produce a conduction delay in the His Purkinje system.

Arrhythmias, Cardiac↗
PubMed1975

Cardiac effects of insulin, glucose, and potassium.

Glucose-insulin-potassium (G.I.P.) infusions have been recommended as a useful adjunct to the management of severe congestive heart failure. Ten patients with cardiac disease underwent a diagnostic cardiac catheterization. Pressures and cardiac output were obtained prior to and immediately after the 10 minute infusion of a mixture containing 50 grams of glucose, 10 mEq of potassium and 20 units of insulin. (Table: see text). G.I.P. infusions can increase the cardiac index. This is due to a combined effect of volume expansion and catecholamine stimulation.

Adult↗