PubMed Health⌕ Search

Biomedical subjects

M F Matangi

Publications and source records attributed to M F Matangi.

11 recordsLinked to original sources

Atenolol for the prevention of arrhythmias following coronary artery bypass grafting.

Seventy patients undergoing aortocoronary bypass grafting were randomized, double-blind, to receive either atenolol or placebo. There were 35 patients in each group. Patients received either atenolol 5 mg intravenously or matching placebo within 3 h of the completion of surgery. A second intravenous dose was administered 24 h following the first and then atenolol 50 mg orally or matching placebo was given for six days. Continuous Holter monitor recordings were obtained for the 24 h immediately preoperatively and continuously for eight days postoperatively. No patient received any antiarrhythmic drug preoperatively. Patients who required pharmacological intervention for the management of postoperative arrhythmias were withdrawn as treatment failures. Holter monitor analysis continued for 24 h following withdrawal of a treatment failure. All patients were analyzed according to the intention-to-treat principle. Both groups were comparable with respect to age, sex, severity of coronary artery disease, left ventricular ejection fraction, preoperative use of beta-blockers, bypass time, aortic cross-clamp time, number of grafts per patient and frequency of preoperative arrhythmias. Arrhythmia analysis was done manually. Supraventricular arrhythmias (atrial tachycardia, atrial fibrillation and atrial flutter) were classified as either mild (less than 0.5 mins, less than 140 beats/min), moderate (0.5 to 30 mins, 140 to 180 beats/min), or severe (longer than 30 mins, more than 180 beats/min). Ventricular arrhythmia analysis was performed with respect to isolated PVCs, couplets, triplets and episodes of nonsustained ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Prophylaxis of post-myocardial infarction dysrhythmias by long-term timolol therapy.

The antiarrhythmic efficacy of timolol maleate was assessed in 94 patients with acute myocardial infarction. No significant differences were noted between early treatment with timolol and placebo in the mean and peak hourly ventricular premature complex rates, ventricular premature complex couplets, or runs. However, compared to the placebo treatment, there was a significant (p less than 0.001) 66% reduction in the relative fraction of early-cycle ventricular premature complexes 7 to 9 days after initiation of timolol therapy and a more prolonged significant (p less than 0.001) 73% reduction in the fraction of early-cycle supraventricular complexes throughout the 28-day timolol and placebo comparison period. The frequency distribution of QRS duration was significantly different between the placebo- and timolol-treated patients, with the mean duration 8 msec longer in the placebo-treated patients (p = 0.008). Adverse effects from early administration of timolol did not differ from those in the placebo-treated patients.

Cardiac Complexes, Premature↗

Myocardial rupture following acute myocardial infarction.

Ten patients, eight males and two females, suffered myocardial rupture following acute myocardial infarction and required surgery. There were five ventricular septal ruptures, four papillary muscle ruptures and one free wall rupture. Ventricular septal rupture was suspected clinically by the appearance of a new systolic murmur, usually associated with a thrill at the left sternal border. A left to right shunt was confirmed by bedside oximetry using a Swan-Ganz catheter. The mean pulmonary to systemic flow ratio was 3.04:1. Following cardiac catheterization all patients underwent corrective surgery with or without aortocoronary bypass grafting. Three patients with inferior wall myocardial infarction died. Papillary muscle rupture was suspected clinically following the abrupt onset of hypotension with severe acute pulmonary edema accompanied by a new systolic murmur. The diagnosis was confirmed by cardiac catheterization. All underwent surgery for mitral valve replacement with or without aortocoronary bypass grafting. One patient died postoperatively of multiorgan failure. Free wall rupture was suspected clinically by the sudden onset of loss of consciousness, apnea, junctional bradycardia and severe hypotension leading to electromechanical dissociation. The diagnosis was confirmed by demonstrating a significant pericardial effusion by two dimensional echocardiography. Immediate surgery was performed. This patient is totally asymptomatic on no drug treatment six months following discharge. Ten patients underwent emergency surgery for myocardial rupture. Operative mortality was 40%. Patients with ventricular septal rupture associated with an inferior myocardial infarction had a poor prognosis.

Aged↗

Elective aortocoronary bypass grafting in the elderly.

Operative mortality, postoperative morbidity and follow up data were analyzed retrospectively from 122 consecutive patients, over 65 years old undergoing elective aortocoronary bypass grafting for symptomatic relief of angina pectoris at the Plains Health Centre, Regina, Saskatchewan, from January 1980 to December 1985. There were two in-hospital deaths (operative mortality 1.6%). Definite perioperative myocardial infarction occurred in 12 patients (9.8%). The 120 survivors were followed for a mean of 32 months. There were three deaths during follow-up, giving a five-year probability of survival of 93%. Twenty-three clinical events (including deaths) occurred during follow-up, giving a five-year probability of event free survival of 72%. Ninety percent of patients say they are pleased with their operation. Seventy-eight percent are currently angina free. These data illustrate the effectiveness of aortocoronary bypass grafting in low risk elderly patients with symptomatic coronary artery disease.

Aged↗

Beneficial effects of atrioventricular synchrony in dogs with right coronary artery embolization, and complete heart block.

Complete heart block complicating right ventricular infarction frequently is accompanied by shock. Hemodynamic responses to different pacing modes were studied in six anesthetized, closed chest dogs following right coronary artery embolization with mercury and heart block induced by repetitive trans-septal DC shock. Hemodynamics were recorded at control, following right coronary artery embolization, during atrioventricular sequential pacing (DVI) and ventricular pacing (VVI). With respect to the hemodynamics recorded during VVI and DVI pacing; (1) The mean arterial pressure increased by 29.4% during DVI pacing (92.1 +/- 31.3 mm Hg vs 73.4 +/- 28.9 mm Hg p less than 0.005). This increase was primarily due to an augmentation in systolic arterial pressure. (2) The left ventricular end diastolic pressure increased by 35.8% during DVI pacing (16.3 +/- 5.3 mm Hg vs 12.0 +/- 4.3 mm Hg p less than 0.01). (3) Cardiac output improved by 33.8% during DVI pacing (2.34 +/- 0.75 L/min vs 1.76 +/- 0.59 L/min, p less than 0.0005). This was a consistent improvement in cardiac output with a narrow range of 27.1% to 39.0%. (4) There were no significant changes in right atrial, pulmonary, pulmonary capillary wedge pressures or in systemic vascular resistance. In dogs with right coronary artery occlusion and complete heart block DVI pacing is clearly superior to VVI pacing. This is probably because the atrial contribution to ventricular filling, in this model, is critically important to maintain an adequate cardiac output.

Animals↗

The nuclear stethoscope.

Eighty consecutive patients undergoing radionuclide gamma camera studies for the measurement of ejection fraction were also examined with the nuclear stethoscope. Overall, the correlation coefficient relating these two techniques was acceptable (r = 0.85). However, two groups were identified: patients with symmetrical wall motion had an excellent correlation (r = 0.90) while patients with regional wall motion abnormalities had a poor correlation (r = 0.78). In conclusion, the nuclear stethoscope is a clinically useful device for monitoring left ventricular function in patients with symmetrical wall motion.

Heart Ventricles↗

Arrhythmia prophylaxis after aorta-coronary bypass. The effect of minidose propranolol.

After aorta-coronary bypass grafting, 164 consecutive patients were randomized to receive propranolol 5 mg every 6 hours orally (n = 82) or to serve as control subjects (n = 82). All patients were receiving beta blockers preoperatively. There were no significant differences between the two groups. The incidence of sustained supraventricular (nonsinus) tachyarrhythmias was 23% in the control group and 9.8% in the treated group (p = 0.02). The incidence of ventricular arrhythmias was 15% in the control group and 2.4% in the treated group (p = 0.005). The overall difference in clinically important arrhythmias was 38% in the control group and 12.2% in the treated group (p = 0.0002). We conclude that low-dose oral propranolol in patients who were receiving beta blockers preoperatively is effective in reducing the incidence of clinically important arrhythmias occurring after aorta-coronary bypass grafting.

Aged↗

Isometric exercise following myocardial infarction.

Twenty-six consecutive patients had measurement of ejection fraction by gated blood-pool imaging at rest and during isometric exercise, following recovery from an uncomplicated myocardial infarction. We found there was a highly significant fall in ejection fraction at rest from 56 +/- 3% to 43 +/- 3% during isometric exercise (p less than 0.0001). There was a dramatic fall in ejection fraction during isometric exercise in some patients with a normal resting value. These patients may be a cause for concern. Our preliminary findings suggest these latter patients are at risk for future cardiac events such as, unstable angina, further myocardial infarction and future coronary bypass surgery.

Adult↗

Subacute cardiac rupture: a surgical emergency.

Three cases of subacute cardiac rupture following acute myocardial infarction are described. All three patients experienced sudden collapse during convalescence and following cardiopulmonary resuscitation were in cardiogenic shock, the shock being due to haemopericardium causing cardiac tamponade. Two of the patients who had electrocardiographic monitoring at the time of their collapse showed nodal bradycardia and were apnoeic and unconscious with no recordable blood pressure (electromechanical dissociation). The diagnosis was confirmed in all three patients by echocardiography which showed pericardial fluid. The patients were referred for urgent cardiac surgery (infarctectomy and Teflon patching) without further investigation. All three patients survived the emergency operation, but two died soon after surgery. The third patient is alive and well five months after the operation.

Cardiac Tamponade↗

Unstable angina with coronary to pulmonary artery fistulae.

Three patients presenting with chest pain were found at cardiac catheterization to have fistulae between the left anterior descending coronary and the main pulmonary artery. Two patients presented with unstable angina, the third with atypical chest pain. Of the two patients presenting with unstable angina both had concomitant coronary artery disease. One was successfully treated with percutaneous transluminal coronary angioplasty. The other underwent successful double aorto-coronary bypass grafting and fistulae ligation. The remaining patient's symptoms resolved after informing him that he did not have atheromatous coronary artery disease. In no patient was the presence of the fistula felt to be related to the patients presenting complaint. In the two patients with unstable angina, a coronary steal phenomenon was postulated as a possible contributing factor.

Adult↗