PubMed Health⌕ Search

Biomedical subjects

G M Froggatt

Publications and source records attributed to G M Froggatt.

5 recordsLinked to original sources

Aspirin, sulfinpyrazone, or both in unstable angina. Results of a Canadian multicenter trial.

We performed a randomized, double-blind, placebo-controlled trial in 555 patients with unstable angina who were hospitalized in coronary care units. Patients received one of four possible treatment regimens: aspirin (325 mg four times daily), sulfinpyrazone (200 mg four times daily), both, or neither. They were entered into the trial within eight days of hospitalization and were treated and followed for up to two years (mean, 18 months). The incidence of cardiac death and nonfatal myocardial infarction, considered together, was 8.6 per cent in the groups given aspirin and 17.0 per cent in the other groups, representing a risk reduction with aspirin of 51 per cent (P = 0.008). The corresponding figures for either cardiac death alone or death from any cause were 3.0 per cent in the groups given aspirin and 11.7 per cent in the other groups, representing a risk reduction of 71 per cent (P = 0.004). Analysis by intention to treat yielded smaller risk reductions with aspirin of 30 per cent (P = 0.072), 56 per cent (P = 0.009), and 43 per cent (P = 0.035) for the outcomes of cardiac death or nonfatal acute myocardial infarction, cardiac death alone, and all deaths, respectively. There was no observed benefit of sulfinpyrazone for any outcome event, and there was no evidence of an interaction between sulfinpyrazone and aspirin. Considered together with the results of a previous clinical trial, these findings provide strong evidence for a beneficial effect of aspirin in patients with unstable angina.

Angina Pectoris↗

Permanent transvenous atrial pacing.

Atrial pacing has electrophysiologic and hemodynamic advantages for patients with symptomatic bradyarrhythmias and intact atrioventricular conduction or with certain refractory tachyarrhythmias. Permanent atrial pacing has been achieved in 29 patients followed up for periods of up to 7 years at two institutions. At Sunnybrook Medical Centre, Toronto, 16 patients have had coronary sinus electrodes introduced pervenously using standard bipolar or special unipolar catheters. Initial pacing thresholds were acceptably low (mean, 2.0 mA); chronic thresholds in three patients were similar. At the Toronto General Hospital, 13 patients had endocardial J-electrodes, bipolar or tined unipolar, inserted in the right atrial appendage. Initial thresholds were low (mean, 1.3 mA) and P-wave voltage was adequate (3.4 mV) for pacemakers with standard sensitivity. In both series, conventional R-inhibited, asynchronous or rate-programmable units have been employed. Radiofrequency self-conversion pacemakers were used in three patients. Preliminary His bundle studies were done in 10 patients; the others were tested by rapid atrial pacing during insertion of electrodes. Early and late electrode stability in both series was excellent; one electrode became dislodged from the coronary sinus position and one from the right atrial appendage.

Adult↗

Total intracardiac repair of the adult cyanotic tetralogy of Fallot: clinical experience and late follow-up.

Twenty-seven adult patients with the cyanotic type of tetralogy of Fallot had total intracardiac repair during the past five years at the Toronto General Hospital. Twenty-one of 27 patients (77%) had had a previous shunting operation performed five to 21 years prior to the total intracardiac repair. Seventeen of 21 (81%) of these anastomoses were patent at the time of the total intracardiac repair. The hospital mortality was 11% and was attributable to hemorrhage - a well-recognized problem in adult tetralogy, due to excessive collateral circulation. All 24 surviving patients followéd up from six months to five years showed marked clinical improvement, with disappearance of the cyanosis and reduction in acne and clubbing. Permanent heart block has not occurred. Late hemodynamic studies showed a significant persisting shunt in two out of 16 or 12%.

Adolescent↗

Cardiac arrhythmias in acute stroke.

Cardiac arrhythmias were more frequent (p less than 0.001) in 312 stroke patients admitted to an intensive care stroke unit, than in 92 patients admitted to the unit and subsequently found not to have strokes. This significant difference remained when a stroke subgroup and the non-stroke group were matched for age, sex and duration of stay in the unit (P less than 0.005). Hypertension and hypertensive cardiac disease were more common in the stroke than in the non-stroke patients (P less than 0.001). Ectopic beats and atrial fibrillation, as well as other arrhythmias, were most frequent in patients with cerebral hemisphere infarction, and patients with hemispheric lesions had significantly more arrhythmias than those with brain stem lesions (P less than 0.05). The arrhythmias were rarely (2%) responsible for hemodynamic ischemic cerebrovascular lesions, but may have been associated with cerebral embolism in up to 17% of cases. The cardiac arrhythmias appeared to have little influence on the course of the subsequent recovery from stroke. Although these arrhythmias frequently reflect the high incidence of cardiac disease in stroke patients, in some cases they are secondary to the acute cerebrovascular lesion itself.

Acute Disease↗