Prognostic significance of the initial electrocardiographic pattern in a first acute anterior wall myocardial infarction

The availability of potent, but potentially dangerous, types of reperfusion therapy for acute myocardial infarction (AMI) has forced us to refine our tools for early and accurate diagnosis and for early risk stratification of patients with evolving AMI. The estimation of risk has to be made shortly after admission, when only the history, physical examination, and the ECG are available. This study was undertaken to compare in-hospital mortality with different patterns of the ECG obtained at admission in 147 consecutive patients with an evolving first AMI of the anterior wall. By using a new classification of the admission ECG, it was possible to divide the patients into 3 groups: (1) group A contained 12 patients with tall peaked T waves in the involved leads, without ST segment elevation; (2) group B comprised 77 patients with abnormal T waves and ST elevation, but without major changes in the terminal portion of the QRS complex; and (3) group C comprised 58 patients with abnormal T waves, ST elevation, and distortion of the terminal portion of the QRS. The mortality was 0, 3 percent, and 29 percent in groups A, B, and C, respectively (chi 2 = 22.91; p = 0). By using a logistic regression model, it was found that the initial ECG pattern alone is a strong predictor of in-hospital mortality in patients with an evolving anterior wall AMI. The predicted probabilities of death in groups A, B, and C are 0.0016, 0.025, and 0.29, respectively. This simple classification of the initial ECG pattern in patients with a first AMI of the anterior wall may enable the differentiation of patients with low in-hospital mortality (groups A and B) and of those with an in-hospital mortality of almost 30 percent (group C).

"Infective" myocardial infarction

Four patients who developed acute myocardial infarction (AMI) in the setting of systemic febrile illness are described. They were all treated with anticoagulants or lytic agents (or both), demonstrating patient coronary arteries following infarction. We discuss the pathogenesis and therapeutic implications of AMI occurring in this setting.

Infarct site-related mortality in patients with recurrent myocardial infarction. SPRINT Study Group

PURPOSE

The purpose of this study was to determine the effect of acute and old myocardial infarction (MI) sites on early (15 days) mortality in patients with a second MI.

PATIENTS AND METHODS

Data are derived from the SPRINT 2 study population that included 1,161 consecutive patients with acute MI, aged 50 to 79 years, recruited from 14 coronary care units in Israel between November 1985 and July 1986. Two hundred twenty-six of these patients (19.5%) had a previous MI prior to the index acute MI. Sixty-two patients were excluded from the analysis either because the MI site was not of anterior or inferior location, or because of incomplete data. In the 164 (73%) remaining patients, acute and old MI locations were determined to be either anterior or inferior and were accordingly divided into 4 groups: acute anterior-old anterior (Group 1-23 patients); acute anterior-old inferior (Group 2-86 patients); acute inferior-old anterior (Group 3-34 patients); acute inferior-old inferior (Group 4-21 patients).

RESULTS

Significant differences in clinical parameters among the four groups included a higher proportion of Q-wave MI (p = 0.04), severe congestive heart failure during admission (p = 0.04), and markedly elevated serum lactate dehydrogenase levels (p = 0.05) in Group 3. High-degree atrioventricular block (p = 0.001) and cardiogenic shock (p = 0.05) also developed more often in this group during hospitalization. Twenty-three patients (14%) died within 15 days. Death rates in the acute anterior (Group 1 plus Group 2) and the acute inferior (Group 3 plus Group 4) groups were 11% versus 20%, respectively (NS). However, death rate variability across the four groups was statistically significant (p = 0.018), with the highest mortality observed in Group 3 (old anterior-acute inferior MI-29%). Multivariate analysis identified acute inferior MI following old anterior MI as a strong independent predictor of early death (relative odds vis-à-vis other combinations 5.0, 95% confidence interval 1.5 to 16.6).

CONCLUSION

This study identifies a subgroup of patients with acute inferior MI at high risk for early mortality. It is possible that such patients would benefit from early reperfusion therapy.

Coronary risk factors in children of parents with premature coronary artery disease

In order to assess the value of family history of premature coronary artery disease as a criterion for coronary risk factor screening, a group of 53 children with such a family history was selected. We determined various coronary risk factors in these children in comparison to 33 controls. Statistically significant differences were observed in apoprotein concentrations but not in concentrations of lipids, lipoproteins or glucose, or in blood pressure or body mass index. The ratio between apoprotein B and apoprotein AI was the best discriminator between the two groups. The predictive value of family history is more reliable for detecting abnormal apoprotein ratio than for detection of hypercholesterolemia. We conclude that if abnormal apoprotein levels during childhood are found to be a valued predictor of premature coronary artery disease, then family history of premature coronary artery disease can be used to select children for determination and assessment of their coronary risk.

ST segment depression in a VL: a sensitive marker for acute inferior myocardial infarction

In a substantial percentage of patients with acute myocardial infarction, especially in those with inferior wall involvement, no ST elevation is detected on the electrocardiogram. In many of them, ST depression is found in leads oriented to remote segments of the heart. The importance of those reciprocal changes for early diagnosis of acute inferior myocardial infarction in patients without ST elevation has not been stressed. In order to find the prevalence of reciprocal ST depression, we evaluated the admission electrocardiograms of 107 consecutive patients with evolving first acute inferior myocardial infarction. Ninety-three patients had ST elevation of at least 0.1 mV in at least one of the inferior leads: II, III or aVF (group A) and in 14 patients ST displacement did not reach 0.1 mV in any of these leads (group B). In both groups, reciprocal ST depression occurred more frequently in aVL than in any other lead. Only three patients had no ST depression in aVL. In eight patients (7.5%) ST depression in aVL was the sole early electrocardiographic sign of the inferior infarction. aVL is the only lead that is facing the superior part of the left ventricle and thus is the only lead that is truly opponent to the inferior wall. It seems that ST depression in aVL, by contrast to that in the precordial leads, is found in the majority of patients with evolving inferior wall myocardial infarction and is not influenced by extension of the infarction to the right ventricle or to the posterior wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of congestive heart failure: neuroendocrine approach

The term heart failure is a complex of clinical syndromes caused by "neuroendocrine" compensatory responses that are renal, neural, hormonal and hemodynamic in nature. Activation of these multiple systems--as a result of renin, angiotensin II and the action of circulatory catecholamines--causes the release of norepinephrine vasopressin and aldosterone. These responses contribute to the arteriolar constriction and salt and water retention that promote central pooling with an increase in pre- and afterload of the already failing heart, causing deterioration of the congestive heart failure (CHF). Therapy for this clinical syndrome is aimed at reducing both pre- and afterload with vasodilators, which produce a profoundly favorable effect on left ventricular performances. Beta blocking agents, which inhibit the increased sympathetic mediated vasoconstriction, up-regulate beta receptors and thus restore responsiveness to the failing heart. Inotropic agents, such as digitalis and amrinone/milrinone are reserved for patients with dilated failing heart and impaired systolic function; recently a synthetic atrial natriuretic factor has been developed for potential use in CHF. Ultrafiltration is also used in refractory preoperative CHF with cardiac abnormalities. Neuroendocrine responses to CHF are treated today directly by improving central hemodynamic imbalance in these patients.

The incidence of atrial arrhythmias during inferior wall myocardial infarction with and without right ventricular involvement

The atrial arrhythmia profile during inferior wall acute myocardial infarction (AMI) has not been systematically examined with respect to right ventricular (RV) involvement. To this end, 62 consecutive patients with first inferior wall AMI and no other conditions known to increase susceptibility for rhythm disturbances were studied by 24-hour Holter monitoring during the first and tenth day of infarction. Based on radionuclear ventriculography performed on day 2 of infarction, patients were allocated to two groups: group A--36 patients (58%) with right ventricular ejection fraction (RVEF) less than 40% (mean +/- SD, 31 +/- 6%) and group B--26 patients (42%) with normal (greater than 40%) RVEF (mean +/- SD, 47 +/- 5%). There were no significant differences between the two groups with respect to age, sex, or left ventricular (LV) function. In the group as a whole, ectopic activity in the different categories of atrial arrhythmias was significantly higher during the first day than on the tenth day of infarction. Comparing the two groups, 33 patients (92%) in group A had a mean hourly frequency of one or more atrial premature contractions (APCs) during the first day of infarction compared with 18 patients (69%) in group B (p less than 0.001). Atrial and supraventricular tachycardia were recorded more frequently in group A patients (16 of 36 [44%] versus 8 of 26 [31%]) as well as atrial fibrillation (AF) (7 of 36 [19%] versus 1 of 26 [4%]). Quantitative analysis showed a similar trend for a higher rate of ectopic events in group A patients. Ectopic activity was neither influenced by LVEF nor by age or sex.(ABSTRACT TRUNCATED AT 250 WORDS)

Ventricular tachycardia of right bundle-branch block--left axis deviation morphology and organic heart disease

Most series of patients with ventricular tachycardia (VT) of right bundle-branch block (RBBB)-left axis deviation (LAD) morphology include young individuals with no overt evidence of structural heart disease. In the present report, the clinical and electrophysiologic findings in two patients with verapamil-responsive VT and organic heart disease are described.

Black scorpion envenomation: two cases and review of the literature

Scorpion envenomation is quite common in India, southeast Asia, the U.S. southwest, and Israel (in the Negev and around Jerusalem). Yellow scorpion is considered the most dangerous scorpion that causes cardiac toxicity. Two patients are described, who lived in a nonendemic area of yellow scorpions and were envenomated by the black scorpion. Both suffered temporary cardiac involvement (manifested by electrocardiographic changes) which reverted to a normal pattern within 24 h. These are the first two cases that have been reported (from black scorpion envenomation) and indicate that the toxin of the black scorpion is also cardiotoxic, but much less than the "yellow scorpion" toxin.

Electrocardiographic Q-waves inconstancy during thrombolysis in acute anterior wall myocardial infarction

It is the purpose of this paper to describe the electrocardiographic inconstancy of Q-waves during administration of thrombolytic therapy. This was documented in four patients given streptokinase early in the course of anterior wall myocardial infarction. Understanding the pathogenesis of sequential dynamic variations of Q-waves in this setting may offer important insights into coronary physiology and management of acute coronary events. We discuss the possible explanations for such changes with respect to tissue viability, dynamic vascular changes and electrophysiological properties of the reperfused infarcted myocardium.

S-T segment depression in right-sided precordial leads during acute inferior wall infarction

Right-sided chest leads (V3-V4R) were recorded in the early stages of first inferior wall acute myocardial infarction (AMI) in 100 consecutive patients. Nine patients (9%) presenting with S-T segment depression (greater than 1 mm) in these leads were subsequently studied by echocardiography and radionuclear angiography. In this group, there were 5 patients with intact right ventricular (RV) function and 4 other patients with clinical findings compatible with RV infarction. We suggest that one should not rule out RV involvement when S-T segment depression rather than elevation is seen in the right precordial leads in the presence of inferior wall AMI. An individual assessment for RV infarction is recommended when this pattern is apparent on the ECG.

Life-threatening ventricular tachycardia as the presenting symptom of metastatic cardiac disease

We present 2 cases in whom repetitive rapid ventricular tachycardia (VT) was the initial manifestation of metastatic cardiac disease. In one patient, repetitive VT appeared during chemotherapy for stage IV paratesticular rhabdomyosarcoma which led to the diagnosis of cardiac metastases. In the other, it led to the diagnosis of malignant pericardial effusion 17 years after successful therapy for a breast carcinoma. In conclusion, in patients with present or past history of malignancy, the appearance of life-threatening VT should raise the suspicion of cardiac metastases.

Prazosin's effect in high renin hypertension complicating pheochromocytoma

During three consecutive days of prazosin treatment in a patient with pheochromocytoma, urinary catecholamine metabolite levels were correlated with plasma renin activity. Suppression of renin plasma activity resulted in sustained hemodynamic and clinical improvement, while no remarkable changes were observed in urinary catecholamine metabolite levels. This suggests that prazosin may interrupt the vicious cycle of worsening hypertension provoked by further activation of the renin-angiotensin system mediated by excessive circulating catecholamines.

Symptomatic bradycardia induced by the combination of oral diltiazem and beta blockers

Ten patients, who were admitted to the Intensive Coronary Care Unit during a one year period with symptomatic bradycardia while on combination therapy with oral diltiazem and beta-blocker agents, are described. The important features of this adverse reaction to drug combination were that it appeared mainly in a relatively elderly age group and with presenting symptoms of lethargy, dizziness, syncope, chest pain, and (in one patient with poor left ventricular function) pulmonary edema. It was not dose dependent and occurred even in very low doses of each drug. Electrophysiologic abnormalities were localized to the sinus node in all 10 patients and the primary rhythm disorders were junctional escape rhythm, sinus bradycardia, and sinus pause. These rhythm abnormalities resolved within 24 h following withdrawal of the offending drugs. Temporary pacemaker insertion was necessary in four patients. The duration of drug combination used before the acute episode range from within hours to up to 2 years. In conclusion, although combination diltiazem/beta blocker therapy is very effective in ischemic syndrome, caution is advised when this combination is used especially in the elderly or in patients with left ventricular dysfunction or antecedent sinoatrial or atrioventricular conduction abnormality.

Ischemia and reperfusion during intermittent coronary occlusion in man. Studies of electrocardiographic changes and CPK release

The course of 357 balloon inflations performed during 38 angioplasties for single-vessel coronary artery disease was prospectively studied using continuous ECG recording. Ischemic ECG changes appeared during 91 percent of the inflations at a mean of 20 +/- 8 seconds after inflation and resolved in 97 percent of those at a mean of 11 +/- 5 seconds after deflation. Elevation of the plasma CPK level was found in six patients who had ischemic ECG changes for at least 7.8 minutes. The duration of ischemia did not exceed 5.4 minutes in any of the patients without CPK elevation. Resolution of the ischemic changes was delayed in patients with CPK elevation and in last vs initial inflations. We conclude that in patients with noninfarcted myocardium, ECG changes follow coronary occlusion and reflow very rapidly, detecting these coronary events with a high sensitivity. Lack of rapid regression predicts lack of reperfusion, and persistence of ischemia for more than 7.8 minutes is sufficient to cause myocardial necrosis.

The impact of right ventricular infarction on the prevalence of ventricular arrhythmias during acute inferior myocardial infarction

To determine the impact of RV infarction on the prevalence and complexity of ventricular arrhythmias during inferior AMI, 57 patients with no prior MI were studied by 24-hour Holter monitoring on the first and tenth days of AMI. Based on radionuclear studies, patients were allocated into two groups: (1) group A, 21 patients (37 percent) with normal RVEF (greater than or equal to 40 percent); and (2) group B, 36 patients (63 percent) with depressed RVEF (less than 40 percent). There were no significant differences between the groups regarding age and LVEF. Values of RVEF were 47 +/- 6 percent and 31 +/- 6 percent, respectively (p less than 0.05). The RVEF had no influence on the prevalence and complexity of early and late arrhythmias. Stratification of patients in group B into two subgroups based on the extent of RV dysfunction did not reveal any differences in the occurrence of all forms of ectopy (when both groups were matched to group A). Therefore, patients with inferior AMI, with or without RV infarction, have a similar prevalence of arrhythmias. Ventricular ectopic beats may be related to the severity and spread of LV involvement, rather than to RV dysfunction.

Late potentials recording with a precordial signal-averaged electrocardiogram in 53 consecutive patients with a first acute myocardial infarction: incidence and early natural history

Signal-averaged electrocardiograms were obtained in 53 consecutive patients with a first acute myocardial infarction (AMI) who survived the first 10 days of hospitalization. The recording was performed twice, at Day 1 and at Day 10 of hospitalization, in patients without bundle-branch block and who did not receive antiarrhythmic therapy. Signal-averaged ECGs were obtained with an instrument which analyzes the presence of late potentials (LP) in each individual precordial lead. There were 41 men and 12 women, mean age of 67 years. On Day 1, three patients had LP (5.6%). On Day 10, LP was recorded in 11 patients (21%). In only one patient was LP transient. Patients who developed LP by Day 10 (absent in Day 1) had statistically significant lower root mean square (rms) voltage and higher QRS duration than patients who did not develop LP on Day 10. In conclusion, in patients with a first AMI who survive the initial hospitalization period and are not in need of antiarrhythmic therapy have an incidence of LP of 21%. A predischarge recording is preferable since this will maximize the chances of detecting LP.

Long-term follow-up of postmyocardial infarction patients with ventricular tachycardia or ventricular fibrillation treated with amiodarone

Amiodarone in a low dose (200 mg/day) was administered alone or in combination with other type I antiarrhythmic drugs as a first-line agent in 33 patients with ventricular tachycardia (VT) (n = 24) or ventricular fibrillation (VF) (n = 9) secondary to coronary artery disease with healed myocardial infarction. There were 30 men and 3 women (mean age 69 +/- 9 years). Left ventricular ejection fraction ranged from 16 to 45% (mean 29 +/- 8). Therapy was guided by the results of electrophysiologic studies without the use of a control study (without drugs). Predischarge electrophysiologic studies revealed inducible sustained VT in 8 patients (24%), nonsustained VT in 7 and noninducible VT in 18 patients. Mean follow-up time was 27 +/- 7 months. Eleven patients (33%) died, 5 suddenly (15%) and 6 from nonarrhythmic causes. Five patients (15%) had nonfatal recurrences of VT. Life-table analysis showed that arrhythmic recurrences or fatalities (VT or sudden death) were related to the results of the predischarge electrophysiologic studies and not to the baseline arrhythmia (VT or VF). Toxicity from amiodarone was uncommon and no patient discontinued taking the drug.

Importance of reciprocal ST segment depression in leads V5 and V6 as an indicator of disease of the left anterior descending coronary artery in acute inferior wall myocardial infarction

The purpose of this study was to determine the coronary angiographic correlations (specifically disease of the left anterior descending coronary artery) of reciprocal ST segment depression appearing during inferior acute myocardial infarction. Forty six patients (41 men and five women; mean age 56 years) were allocated into two groups based on the extent of precordial ST segment depression: widespread (V1-V6) ST depression v localised (V1-V4) ST depression. Patients with no reciprocal ST depression or patients with ST depression in V1-V4 but with ST elevation in V5 and V6 (inferolateral acute myocardial infarction) were excluded. All patients were catheterised during hospital admission for infarction. Twenty four of the 28 patients with ST depression in V1-V6 had significant lesions in the left anterior descending coronary artery whereas 16 of the 18 patients with ST depression in V1-V4 had insignificant or no lesions in the left anterior descending artery. The sensitivity, specificity, and positive and negative predictive values of widespread ST depression in predicting disease in the left anterior descending coronary artery were 92%, 80%, and 86% and 89% respectively. In patients with inferior acute myocardial infarction and precordial ST depression, the extent of ST depression is of clinical significance. Widespread (V1-V6) ST depression suggests disease of the left anterior descending coronary artery, whereas localised ST depression (V1-V4) indicates its absence.