Myron H. Luria

Prevention of Myocardial Damage in Acute Myocardial Ischemia by Early Treatment with Intravenous Streptokinase

We evaluated the effectiveness of early intravenous administration of 750,000 units of streptokinase in 53 patients with acute myocardial ischemia treated by a mobile-care unit at home (9 patients) or in the hospital (44 patients). Treatment was begun an average (+/- S.D.) of 1.7 +/- 0.8 hours from the onset of pain. Non-Q-wave infarctions developed subsequently in eight patients, whereas all the others had typical Q-wave infarct patterns. In 81 per cent of the patients the infarct-related artery was patent at angiography performed four to nine days after admission. Vessel patency was independent of the time of treatment, but residual left ventricular function was time dependent. Patients treated less than 1.5 hours after the onset of pain had a significantly higher ejection fraction (56 +/- 15 vs. 47 +/- 14 per cent; P less than 0.05) and infarct-related regional ejection fraction (51 +/- 19 vs. 34 +/- 20 per cent; P less than 0.01) and a lower QRS score (5.6 +/- 4.9 vs. 8.6 +/- 5.5; P less than 0.01) than patients receiving treatment between 1.5 and 4 hours after the onset of pain. Patients treated earlier by the mobile-care unit also had better-preserved left ventricular function than patients treated in the hospital. We conclude that thrombolytic therapy with streptokinase is most effective if given within the first 1.5 hours after the onset of symptoms of acute myocardial infarction.

Importance of long-duration postoperative ST-segment depression in cardiac morbidity after vascular surgery

Major vascular surgery is associated with a high incidence of cardiac ischaemic complications. By means of continuous perioperative electrocardiographic recording, we studied 151 consecutive patients undergoing major vascular surgery to find out the characteristics of any myocardial ischaemia and the relation to outcome. 13 (8.6%) patients had postoperative cardiac events (6 myocardial infarctions, 2 unstable angina, and 5 congestive heart failure). There were 342 perioperative ischaemic episodes shown by ST-segment depression; 164 (48%) occurred postoperatively. Postoperative ischaemic episodes were significantly longer than episodes before or during operations (3.2 vs 1.7 and 1.5 min per h monitored, respectively, p < 0.001). Both Detskys cardiac risk index and long-duration (> 2 h) preoperative ischaemia were predictive of postoperative cardiac complications (odds ratios in univariate analysis 3.3, p = 0.03, and 7.2, p = 0.009, respectively). However, long-duration (> 2 h) postoperative ischaemia was the only factor significantly associated with cardiac morbidity in multivariate logistic regression analysis (odds ratio 21.7, p = 0.001). Long-duration ST-segment depression preceded most (84.6%) postoperative cardiac events, including myocardial infarctions, and no cardiac event was preceded by ST-segment elevation. 5 of the 6 postoperative myocardial infarctions were non-Q-wave infarctions. We conclude that long-duration subendocardial ischaemia, rather than acute coronary artery occlusion, may bring about postoperative myocardial injury and complications.

Ventricular Aneurysm A Reappraisal Based on a Study of Sixty-Five Consecutive Autopsied Cases

Sixty-five consecutive autopsied cases of ventricular aneurysm are reviewed. The incidence of aneurysm following myocardial infarction is similar to that reported in other series. Myocardial infarction preceded the formation of an aneurysm of the ventricle in the vast majority of patients, and a new myocardial infarction was the cause of death of about 50 per cent of them. The survival rate of patients with ventricular aneurysm is not significantly different from the long-term survival of all patients with myocardial infarction found in the same institution. Complications of ventricular aneurysm such as chronic congestive heart failure and rupture of the aneurysm were infrequent causes of death, and systemic embolic phenomena were not observed as a cause of death. In only four patients was the diagnosis made ante mortem. The lack of characteristic clinical, radiologic, and electrocardiographic findings is discussed. It is suggested that the hemodynamic significance of ventricular aneurysms is not ordinarily great, in view of the unaffected statistical prognosis in its presence. The recommended indications for surgery of ventricular aneurysms, based on this retrospective study, are presented.

Early heart rate variability alterations after acute myocardial infarction.

In order to assess early changes in heart rate variability, we studied 81 patients with acute myocardial infarction during the initial 24 hours after thrombolytic therapy. The standard deviation of the mean heart rate and the low (0 to 0.05 Hz), mid (0.05 to 0.20 Hz), and high (0.20 to 0.35 Hz) frequency band power were evaluated with 24-hour ECG Holter recordings. We found diminished variance in the time domain and reduced power spectrum in the frequency domain compared with a group of 41 normal subjects (p < 0.01). Patients with anterior infarction had significantly (p < 0.01) higher heart rates and lower heart rate variability values than patients with inferior infarction. Reduction in heart rate variability occurred within the first 8 hours in patients with anterior infarction; a significant fall (p < 0.03) was especially noted in the high-frequency band after a decline in ST-segment elevation. Heart rate variability alterations in patients with inferior infarction were most evident in the final 8-hour interval. These findings may be viewed in terms of sympathovagal imbalance and may be related to clinical signs of intense autonomic nervous system activity that are observed early in the course of acute anterior and inferior myocardial infarction.

Bradycardia and hypotension following reperfusion with streptokinase (Bezold-Jarisch reflex): A sign of coronary thrombolysis and myocardial salvage

Acute myocardial infarction, particularly of the inferior wall, is frequently associated with bradycardia and hypotension. This study reports the occurrence of transient bradycardia hypotension (TBH) (Bezold-Jarisch reflex) following thrombolytic therapy with intravenous streptokinase. Of the 52 patients, 42 had successful reperfusion, and 12 of the latter developed reflex TBH. The Bezold-Jarisch reflex occurred in 10 of 24 patients with inferior wall acute myocardial infarction and in 2 of 28 patients with anterior wall infarction (p less than 0.05). The reflex was associated with significantly more non-Q wave infarctions (p less than 0.05) and also with reduction of left ventricular damage, as evidenced by a lower QRS score (4 +/- 3.8 vs 8.9 +/- 5.6, p less than 0.01) and a higher ejection fraction (61 +/- 13% vs 49 +/- 16%, p less than 0.05). Patients with inferior wall acute myocardial infarction were divided into those with TBH (10 patients) and those without TBH (14 patients). TBH was associated with a significantly higher infarct-related regional ejection fraction (60 +/- 19% vs 35 +/- 18%, p less than 0.05). The results of this study confirm previous findings that reperfusion of the inferoposterior myocardium is capable of stimulating reflex TBH. Furthermore, TBH is associated with patency of infarct-related coronary arteries and myocardial salvage.

Day vs night ECG and heart rate variability patterns in patients without obvious heart disease

The day vs night values of variables that may be related to the autonomic nervous system were compared in 50 individuals without obvious heart disease. Using ambulatory electrocardiographic monitoring and heart rate variability analysis, it was found that in contrast to daytime, nocturnal heart rate and total heart rate variability were reduced and low (0-0.05 Hz) and high (0.2-0.35 Hz) frequency power of nocturnal heart rate variability were increased, whereas mid-frequency (0.05-0.2 Hz) power was reduced. In addition, nocturnal episodes of trapezoidal-shaped waveforms of heart rate increase were present primarily at night and ST was elevated to a greater extent at night. Many of these factors were related to age and tentatively, despite the small sample size, reflect an age-related diminished autonomic nervous system response. These results serve to establish a circadian basis for comparison when evaluating disease states such as ischemic heart disease and its prognosis.

Acute and Chronic Effects of an Adrenergic Beta-Receptor Blocking Agent (Propranolol) in Treatment of Cardiac Arrhythmias

The effects of intravenous and oral administration of propranolol, an adrenergic beta-receptor blocking agent, have been studied in 29 patients with various cardiac arrhythmias. The ventricular responses in chronic or paroxysmal ectopic supraventricular arrhythmias were decreased at rest or during exercise. Sinus tachycardias were regularly slowed. Two supraventricular tachycardias and one ventricular tachycardia, all consistently precipitated by exogenous stimuli, were prevented. Six instances of digitalis-induced arrhythmias were responsive to treatment.Propranolol, especially when given orally, is of definite value in selected disturbances of cardiac rhythm. Reasonable caution should be exercised, however, because of the risk of precipitation of congestive heart failure or hypotension in patients with limited cardiac reserves.

Preoperative Thallium Scanning, Selective Coronary Revascularization, and Long-Term Survival After Carotid Endarterectomy

BACKGROUND AND PURPOSE Long-term survival in patients after carotid endarterectomy (CEA) is determined mainly by their concomitant cardiac disease. We tested to determine whether preoperative thallium scanning (PTS) and subsequent selective coronary revascularization (CR), by either percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG), improve long-term survival after CEA. METHODS Two hundred twenty-six of 255 consecutive patients (88%) undergoing CEA from 1990 to 1996 had PTS. Those with significant reversible defects on PTS were referred for coronary angiography and possible CR. Patients who had undergone PTS were divided into the following 4 groups: group 1, normal or mild defects on PTS; group 2, moderate-severe fixed and/or reversible defects in patients who did not undergo CR; group 3, patients who had CR secondary to their PTS results; and group 4, patients who had CR in the past that was not related to the PTS. Perioperative data were prospectively recorded, and data on long-term survival and cardiac and neurological complications were collected. RESULTS Seventy-seven patients (34%) had preoperative coronary angiography, and 42 (19%) had subsequent CR: preoperative PTCA or CABG in 24, combined CEA+CABG in 10, and post-CEA CABG in 8 patients. No deaths resulted from the coronary angiography, CR, or CEA. Six patients had perioperative nonfatal myocardial infarction and 8 had stroke. During the follow-up (40+/-23 months), 47 patients (18%) died, 31 (66%) from cardiac disease and 4 (8.5%) from stroke. Independent predictors of long-term overall mortality were diabetes mellitus, preoperative T-wave inversion on ECG, lower-extremity arterial disease, and history of neurological symptoms [exp(beta)=3. 5, 3.4, 2.5, and 2.4; P=0.0003, 0.0004, 0.01, and 0.04, respectively]. In addition, preoperative moderate-severe thallium defect without CR (group 2) independently predicted long-term cardiac mortality [exp(beta)=2.8; P=0.04]. Patients with preoperative CR (group 3) had long-term survival rate similar to that of group 1 and significantly better than that of group 2 (P=0. 02). CONCLUSIONS PTS predicts long-term survival, and selective CR based on the thallium results improves the survival rate of patients undergoing CEA.

Successful Therapy of Prolonged Hypotension with an Adrenergic Beta-Receptor Blocking Agent

Two patients with prolonged hypotension requiring continuous vasopressor therapy are described.In both patients treatment with nethalide, a beta-receptor blocking agent, appeared clinically effective in allowing the withdrawal of metaraminol therapy and the maintenance of normotension. The results in these patientstend to fortify a hypothesis of peripheral adrenergic beta-receptor dominance in patients with prolonged hypotension.

Prolonged postoperative myocardial ischaemia and infarction in vascular surgery performed under regional anaesthesia

The importance of prolonged postoperative myocardial ischaemia in cardiac outcome has recently been emphasised. The present study examines the correlation between perioperative ischaemia and myocardial infarction (MI) in patients undergoing peripheral vascular surgery (PVS) under regional anaesthesia. One-hundred-and-forty consecutive peripheral vascular operations under regional anaesthesia were prospectively analysed, using Holter monitoring for perioperative myocardial ischaemia (defined as down sloping or horizontal ST-segment depression of > or = 1 mm) and postoperative cardiac outcome. The study was approved after informed consent. There were 82 carotid endarterectomies under cervical block and 58 infrainguinal bypass procedures under continuous spinal or epidural anaesthesia. IHD was present in 53.6% cases: previous MI-38%; angina pectoris-33%; previous CABG/PTCA-24%. Holter monitoring started about 20 hours before surgery and continued for 45 hours. After surgery patients were followed for signs of cardiac complications; daily 12 lead ECG; 6 hourly CK-MB isoenzymes during the first 24 postoperative hours and later whenever indicated. MI diagnosis was based on chest pain, permanent new ECG changes and CK-MB elevation. There was no 30-day mortality. Postoperative MI occurred in seven patients (5%). Five of the postoperative MI were non-Q-wave infarctions. The majority (71%) of the adverse cardiac events started within 24 hours of surgery, and the latest occurred 52 and 72 hours post surgery. In 65 cases (46.4%) there were 259 episodes of significant ST-depression. In 75 (53.6%) cases ischaemic episodes were not detected. Patients with postoperative cardiac events had significantly more and longer ischaemic episodes in all three perioperative periods than those without such events.(ABSTRACT TRUNCATED AT 250 WORDS)