Renato G. Ramos

A Prospective Randomized Clinical Trial of Intracoronary Streptokinase versus Coronary Angioplasty for Acute Myocardial Infarction

We randomly assigned 56 patients who presented within 12 hours of their first symptoms of acute myocardial infarction to treatment with either intracoronary streptokinase or coronary angioplasty. The mean (+/- SD) duration of symptoms (3.0 +/- 1.2 hours in the group treated with angioplasty vs. 3.6 +/- 1.8 in the group treated with streptokinase; P not significant) and time to recanalization (4.1 +/- 1.4 hours vs. 4.8 +/- 1.7 hours; P not significant) were similar in both groups. Coronary recanalization was achieved in 83 percent of the patients treated with angioplasty and in 85 percent of those treated with streptokinase (P not significant). Residual luminal stenosis in the coronary artery was significantly decreased after angioplasty, as compared with streptokinase therapy (43 +/- 31 percent of patients vs. 83 +/- 17; P less than 0.001). Residual stenosis of 70 percent or more was present in 4 percent of the angioplasty-treated patients and in 83 percent of the streptokinase-treated patients (P less than 0.01). Ventricular function after therapy was assessed by serial contrast ventriculograms. Increases in both global ejection fraction (8 +/- 7 percent vs. 1 +/- 6; P less than 0.001) and regional wall motion (+1.32 +/- 1.32 SD vs. +0.59 +/- 0.79 SD; P less than 0.05) were greater for the angioplasty group. We conclude that angioplasty and streptokinase produce similar rates of early coronary reperfusion during evolving transmural myocardial infarction. However, angioplasty is significantly more effective in alleviating the underlying coronary stenoses, and this may result in more effective preservation of ventricular function after therapy.

Sequence of mechanical, electrocardiographic and clinical effects of repeated coronary artery occlusion in human beings: Echocardiographic observations during coronary angioplasty

The direct manipulation of coronary blood flow to induce regional myocardial ischemia has been almost entirely limited to experimental animal models. Thus, the detection of ischemia-induced left ventricular dysfunction in human subjects has been generally limited to observations made under conditions of diagnostic loading or during spontaneous clinical events. Percutaneous coronary angioplasty requires repeated interruptions of coronary blood flow for periods as long as 1 minute. The resulting appearance of or increase in ischemia-produced changes in myocardial function were detected by two-dimensional echocardiography in 18 patients undergoing angioplasty of 22 coronary stenoses. Accordingly, left ventricular contraction was studied during 52 episodes of regional coronary blood flow interruption and reperfusion in the process of inflating and deflating the angioplasty balloon. Before angioplasty, left ventricular wall motion was normal in 14 patients. There was mild anteroapical hypokinesia in two patients, anteroapical akinesia in one and mild inferior hypokinesia in one. Balloon inflations repeatedly produced new or increased wall motion abnormalities in the distribution of the instrumented coronary artery in 19 (86.4%) of the 22 procedures, but did not alter wall motion during angioplasty of one left circumflex artery lesion, one highly collateralized left anterior descending artery stenosis and one left anterior descending stenosis that had already caused severe anteroapical dyssynergy. Hypokinesia, usually rapidly progressing to dyskinesia, began 19 +/- 8 seconds (mean +/- SD) after coronary occlusion. Wall motion began to normalize 17 +/- 8 seconds after reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of Patients with Acute Myocardial Infarction Who Are Ineligible for Thrombolytic Therapy

OBJECTIVE To determine what proportion of patients with acute myocardial infarction are not eligible for thrombolytic therapy and to assess their natural history. DESIGN Retrospective chart review. SETTING A large community-based hospital. PATIENTS All patients with acute myocardial infarction hospitalized during a 27-month period. MEASUREMENTS Of 1471 patients with acute myocardial infarction, 230 (16%) received thrombolytic therapy according to the protocol and an additional 97 (7%) received nonprotocol thrombolytic therapy, primary coronary balloon angioplasty, or both because of contraindications. The other 1144 patients (78%) did not receive reperfusion therapy. MAIN RESULTS The patients who did not receive thrombolytic therapy were older, more likely to be women, and more likely to have a history of hypertension, previous myocardial infarction, or chronic angina (all comparisons, P less than 0.002). An average of 1.9 reasons for exclusion were identified per patient among the ineligible patients. Mortality was fivefold higher among ineligible patients (19%; Cl, 16% to 21%) than among protocol-treated patients (4%; Cl, 1% to 6%) (P less than 0.001). In-hospital mortality rates for excluded patients were 28% (Cl, 23% to 32%) in elderly patients (age, greater than 76 years; n = 396); 29% (Cl, 23% to 35%) in patients with stroke or bleeding risk (n = 209); 17% (Cl, 14% to 20%) in patients with delayed presentation (greater than 4 hours after the onset of chest pain; [n = 599]); 14% (Cl, 11% to 16%) in patients with an ineligible electrocardiogram (ECG) (n = 673); and 26% (Cl, 21% to 32%) in patients with a miscellaneous reason for exclusion (n = 243). Independent predictors of increased mortality were: age greater than 76 years, stroke or other bleeding risk, ineligible ECG, or the presence of two or more exclusion criteria. CONCLUSIONS Thrombolytic therapy is currently used in the United States for only a minority of patients with acute myocardial infarction: those who have low-risk prognostic characteristics.

Intracoronary streptokinase in clinical practice.

The candidacy for streptokinase (SK) infusion was studied in 95 patients displaying ECG evidence of acute or impending infarction who were catheterized within 5 hours of the onset of chest pain. Intracoronary SK was administered to 84 patients in whom occlusions of the infarct-related vessel were identified, with early recanalization having been achieved in 74 (88%). Because of completeness of studies, a data base of 72 patients was employed for further analysis. Recanalization was sustained at follow-up in 45 of 55 patients (82%). Spontaneous thrombolysis was demonstrated at follow-up in five patients (8%) initially resistant to SK, and rethrombosis occurred in 10 patients (18%). Preservation of R waves relative to Q wave depth was limited to patients with less than 90% residual stenosis. Eight of nine patients with continuing thrombolysis and patients with recanalized occlusions of the left anterior descending coronary artery displayed more impressive increases in mean (+/- SEM) ejection fraction (47% +/- 4% to 53% +/- 5% [p less than 0.05], and 47% +/- 3% to 52% +/- 5, respectively). The ejection fraction also increased significantly in 15 patients with pre-SK values of less than 50% (41% +/- 2% to 48% +/- 3%; p less than 0.05). Ventricular function deteriorated in SK failures. Reperfusion arrhythmias occurred in 28 of 62 recanalized patients (45%). Minor bleeding tendencies were displayed in 18 of 72 patients (25%). Major hemorrhages, one of which may have been fatal, occurred in four patients (5.6%). Of 84 patients, four (4.7%) died, two of whom were in cardiogenic shock when first seen. In contrast, there were 11 deaths (11.8%) in a consecutive simultaneously enrolled series of 93 control patients with similar entry criteria (p less than 0.05). Two additional SK-treated patients died, 16 and 30 days after treatment, both more than a week after surgical revascularization. It is concluded that SK recanalization is a promising new therapy that may decrease mortality and preserve myocardial function in certain circumstances. Its efficacy in a setting closer to the mainstream of cardiologic practice extends the favorable experience issuing from earlier clinical investigations.

Aneurysm of the atrial septum as diagnosed by echocardiography: Analysis of 11 patients

Atrial septal aneurysm (ASA) is considered uncommon and, when discovered, has usually been found in association with other cardiac lesions.1-4 This association has led some observers to conclude that their occurrence is the result of an increased pressure gradient between the atria producing a bulging septal shift toward the low pressure side.1*2 In contrast, Silver and Dorsey5 detected clinically silent aneurysm of the septum primum in 16 of 1,578 serially autopsied adults. Only 1 of their 5 hemodynamically studied patients had elevated left ventricular end-diastolic pressure. Atrial septal aneurysm has been found by 2dimensional echocardiography (2-D echo) in association with various congenital and acquired valvular diseases.334 A patient who had a myocardial infarction and ASA with phasic inspiratory right-to-left motion of the aneurysm was reported.6 Isolated case reports of ASA associated with a midsystolic click,7 and with no associated lesions,” have also been recently reported. The subject of our report is 11 cases of ASA shown by 2-D echo to exist in the absence of other identifiable structural cardiac abnormalities.

Early hospital discharge after percutaneous transluminal coronary angioplasty

To determine the safety and efficacy of early hospital discharge after percutaneous transluminal coronary angioplasty (PTCA), 100 patients were studied prospectively. A telemetry observation unit was established to monitor patients having uncomplicated procedures. A total of 170 lesions were dilated, with a procedural success rate of 96% and a clinical success rate of 91%. There were no deaths or patients who required emergency bypass surgery. Four patients developed abrupt vessel closure in the catheterization laboratory. No major complications developed in the telemetry observation unit or after discharge. Patients with high-risk lesion morphology, based on the American College of Cardiology/American Heart Association Task Force guidelines, tended to have a lower success rate and more procedural complications. Coronary dissections were angiographically detected in 33 patients and stratified into 6 types. To reduce possible adverse sequelae, all patients with complex dissections were triaged in the catheterization laboratory to an in-patient monitored unit for additional management. Accordingly, 20 patients were admitted to an in-patient unit for extended observation. Excluding 4 patients with myocardial infarction, 75% (12 of 16) were discharged the next day. Initial experience with early discharge suggests that under proper conditions the procedure is safe and effective. Patients with complex coronary dissections who are at high risk for abrupt vessel closure can be promptly identified after dilatation and triaged to an appropriate monitoring area. Early discharge after PTCA offers more efficient use of hospital facilities and the opportunity to reduce hospital costs.

Ethanol-Induced Changes of Myocardial Performance in Healthy Adults

The acute cardiac effects of ethanol (ETOH) have been studied in 32 normal volunteers. 40–60 min after completion of the consumption of an average 6 oz of 100 proof (50 %) vodka, mean serum ETOH level

The relative resistance of normal young women to ethanol-induced myocardial depression.

In contrast to previous reports from our own laboratory utilizing systolic time intervals (STI) and by others using ultrasound, no evidence of acute myocardial depression was observed in response to an ethanol (ETOH) dose of 1.25 ml/lb consumed over a period of 60 minutes by 6 young women (22.7 ± 7 years; 133 ± 6 lbs) who were monitored for 3 hours thereafter. Specifically, there was no significant change in fractional shortening (%ΔD), ejection frac tion, or mean circumferential fiber shortening velocity. Cardiac index and stroke index also remained stable, although heart rate increased (P < 0.005) and systolic and diastolic blood pressure fell (P < 0.01 and 0.25 respectively). To examine further this unanticipated cardiac resistance to ETOH, we re- examined the sex-specific difference of STI response to acute ETOH exposure in a previously reported group of 32 normal subjects (20 men and 12 women). Significant increases in PEP, PEPI, ICT, and PEP/LVET (P < 0.005, 0.005, 0.005, and 0.001 respectively) were observed in men only. Because we have previously observed that chronic ETOH consumption blunts acute myocardial depression, and because only 1 of 7 STI subjects historically consuming the least ETOH (< 1 oz/day) was a woman, STIs, were reassessed only in those subjects with a chronic consumption of 1 or more oz/day (14 men and 11 women). Myocardial depression as estimated by an increased ICT (P < 0.05) and PEP/ LVET (P < 0.02) was again observed in men only. We concluded that women are less susceptible than men to acute ETOH induced myocardial depression, as has recently been suggested for chronic ETOH consumption as well.

Reassessment of Q waves in left bundle branch block

This study disputes a number of recent reports claiming that abnormal Q waves or a QS configuration in inferior leads (II, III and AVF) coexisting with left bundle branch block is highly suggestive of, and indeed specific for, myocardial infarction. Five patients reported herein demonstrate disappearance of Q waves in inferior leads on spontaneous reversal of LBBB to normal conduction. This necessitates the conclusion that these Q waves represent a postdivisional conduction variant most closely equivalent to left anterior fascicular block coexisting with predivisional LBBB. Absence of inferior R waves in the five patients demonstrating LBBB is explicable by as little as a 20 msec conduction delay in the posterior fascicle coexisting with a higher grade conduction defect in the anterior fascicle. It is concluded that LBBB with a QS configuration in II, III and AVF cannot be considered diagnostic of inferior wall infarction since it regularly results from impaired conduction of the left anterior and possibly the left posterior fascicle (to a lesser extent), which may be reversible.

Associated reactions during and immediately after rtPA infusion

The complications of IV recombinant tissue-type plasminogen activator (rtPA) have not been previously reported specifically for the first hours after initiation of the therapy when patients are often in emergency departments or in transport. The charts of 124 patients who received rtPA between April 1986 and December 1987 were retrospectively reviewed for reactions associated with rtPA infusion occurring in the first ten hours after the onset of rtPA administration. Minor bleeding developed in 19% of the patients, and life-threatening bleeding in 3%. Half of the life-threatening bleeding episodes were not predictable by history or physical examination. Arrhythmias were frequent despite the fact that all patients were maintained on IV lidocaine. New premature ventricular contractions occurred in 67%, accelerated idioventricular rhythm in 34%, ventricular tachycardia in 30%, and ventricular fibrillation in 2%. Many of the arrhythmias other than ventricular fibrillation had little hemodynamic consequence and did not require treatment. Neurologic episodes occurred in 3%, including two patients with intracerebral bleeding (1.5%); hypotension requiring treatment developed in 3%; and minor symptoms of allergy in 2%. Administration of rtPA in the ED requires careful patient selection to avoid bleeding complications and close monitoring to detect arrhythmias and changes in vital signs.