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Biomedical subjects

Y Birnbaum

Publications and source records attributed to Y Birnbaum.

At least 109 records · Page 6Linked to original sources

ST segment depression in lateral limb leads in inferior wall acute myocardial infarction. Implications regarding the culprit artery and the site of obstruction.

We examined whether the pattern of ST segment depression in lateral leads (I, aVL, V5, V6) in the initial electrocardiogram of patients (n = 88) with inferior wall acute myocardial infarction (ST segment elevation of > or = mm in > or = 2 inferior leads) correlates with the site of obstruction, as determined angiographically during acute hospitalization. Of the 62 patients in which the culprit artery could be determined unequivocally, in 46 the culprit artery was the right coronary artery (20 proximal to the first right ventricular branch and 26 distal), and in 16 the left circumflex coronary artery (seven proximal to the first marginal branch or involving a high first marginal branch, and nine with distal obstruction). Significant ST segment depression (ST < or = 1 mm) in leads I and aVL was more common in right coronary artery obstruction (P < 0.05 and P < 0.0001, respectively). The absence of significant ST segment depression in lead aVL was most common in proximal circumflex obstruction (P < 0.0001), with a similar trend for lead I (P < 0.11). ST segment depression patterns in leads V5 and V6 were not indicative of the infarct-related artery or the site of obstruction. Thus, significant ST segment depression in leads I and aVL indicates right coronary artery-associated inferior wall acute myocardial infarction with a sensitivity of 70% and 100%, and a specificity of 63% and 38%, respectively, whereas the lack of ST segment depression in these leads indicates proximal circumflex obstruction with a sensitivity of 71% and 86%, and a specificity of 65% and 100%, respectively.

Coronary Angiography↗

Inferior wall acute myocardial infarction with one-lead ST-segment elevation: electrocardiographic distinction between a benign and a malignant clinical course.

BACKGROUND: In most clinical trials, ST-segment elevation in two contiguous leads is required for diagnosis of acute myocardial infarction (AMI). This study describes the clinical course of patients with inferior wall AMI with one-lead ST-segment elevation in lead L3 in the initial ECG. METHODS: Of 394 consecutive patients with inferior wall AMI, 31 (7.8%) had an initial ECG showing ST-segment elevation (+/- 1 mm) only in lead L3 (ST < 1 mm in leads L2 and aVF) and upright T waves in inferior leads. Patients were categorized into three groups: (I) no precordial ST-segment depression (n = 6), (II) maximal precordial ST-segment depression in leads V1-V3 (n = 4), and (III) maximal precordial ST-segment depression in leads V4-V6 (n = 21). RESULTS: Patients in group III developed severe heart failure (pulmonary edema or cardiogenic shock) six times more frequently than those in groups I-II (62 versus 10%). Among patients who underwent coronary angiography, three-vessel coronary artery disease (> 50% stenosis) was more common in group III. Five of six patients in group III who underwent emergency angioplasty of the right coronary artery because of cardiogenic shock survived. CONCLUSION: Patients with inferior wall AMI and an initial ECG with ST-segment elevation only in lead L3, and maximal precordial ST-segment depression in leads V4-V6, are at risk of severe complications, especially heart failure, but their clinical course may be ameliorated by employing an aggressive interventional strategy.

Adult↗

Prognostic significance of maximal precordial ST-segment depression in right (V1 to V3) versus left (V4 to V6) leads in patients with inferior wall acute myocardial infarction.

This study examines whether patients with inferior wall acute myocardial infarction (AMI) and maximal ST-segment depression in left precordial leads are at higher risk for in-hospital mortality. The charts of patients (n = 213) with inferior wall AMI and an initial electrocardiogram that displayed peaked, tall T waves or ST-segment elevation with upright T waves in inferior leads were reviewed, after excluding patients with inverted T waves in inferior leads (n = 75). ST-segment deviation from baseline was measured for all leads. Patients were classified into 3 types: I = no precordial ST-segment depression; II = sum of ST-segment depression in leads V1 to V3 equal to or more than the sum of ST-segment depression in leads V4 to V6; and III = maximal precordial ST-segment depression in leads V4 to V6. Thirty-six patients (17%) died in the hospital. In-hospital mortality rates for patients with types I and II were 12% and 10%, respectively, compared with 41% for those with type III (p < 0.0001). Mortality rates in surviving patients were similar for all types up to 1 year after infarction. Multivariate logistic regression models for in-hospital mortality by ST-segment depression type adjusted for age, previous AMI, diabetes mellitus, and thrombolytic therapy revealed that type III pattern was a strong predictive factor for in-hospital mortality (odds ratio = 4.9, p = 0.0008, 95% confidence interval 1.93 to 12.26). Thus, patients with inferior wall AMI and maximal precordial ST-segment depression in leads V4 to V6 are at high risk for in-hospital mortality.

Aged↗

Clinical significance and predisposing factors to symptomatic bradycardia and hypotension after percutaneous transluminal coronary angioplasty.

Of 180 consecutive patients who underwent uneventful percutaneous transluminal coronary angioplasty (PTCA), 25 (13.9%) had at least 1 episode of symptomatic bradycardia and hypotension during the early postprocedure period. Symptomatic bradycardia and hypotension occurred 1 to 10 hours (mean 4 +/- 2) after PTCA. A higher incidence of symptomatic bradycardia and hypotension was found in patients receiving regular treatment with beta blockers (26% vs 10% in patients without beta blockers in their regimen, p < 0.01), diltiazem or verapamil (20% vs 9%, p < 0.025), or both a beta blocker and diltiazem or verapamil (64% vs 11%, p < 0.001). A higher incidence was also associated with angioplasty of the left anterior descending coronary artery compared with angioplasty of the other coronary arteries (22% vs 8%, p < 0.01). It is concluded that symptomatic bradycardia and hypotension is a common occurrence after PTCA. The incidence is higher after PTCA to the left anterior descending coronary artery and in patients receiving diltiazem, verapamil, and beta-blocking agents; it is particularly high in patients receiving a combination of a beta-blocking agent and either diltiazem or verapamil.

Adrenergic beta-Antagonists↗

Implications of inferior ST-segment depression in anterior acute myocardial infarction: electrocardiographic and angiographic correlation.

This study assesses the significance of inferior ST-segment depression during anterior acute myocardial infarction (AMI) by investigating the relationship between inferior ST-segment depression and (1) the site of the left anterior descending (LAD) coronary artery lesion and (2) ST-segment deviation in the various anterior and lateral leads. We studied 126 patients with anterior AMI who underwent coronary angiography within 21 days of hospitalization. The admission 12-lead electrocardiograms were evaluated for ST-segment amplitude in each lead at 0.08 second after the J-point. Coronary angiography was evaluated for the site and severity of luminal narrowing of the coronary arteries. The site of the culprit lesion in the LAD artery, relative to the origin of the first septal and diagonal branches, was determined. In four patients no lesion was identified in the LAD artery. Of the remaining 122 patients, 40 and 53 patients had a LAD artery lesion proximal to the first septal and first diagonal branches, respectively. Additional luminal narrowing (> or = 70% of diameter) was found in the circumflex and the right coronary arteries in 27 and 37 patients, respectively. ST-segment depression of > 1 mm in leads II, III, and aVF was noted in 24, 29, and 24 patients, respectively. The prevalence of a LAD artery preseptal and prediagonal lesion was higher in patients with inferior ST-segment depression.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Isolated mid-anterior myocardial infarction: a special electrocardiographic sub-type of acute myocardial infarction consisting of ST-elevation in non-consecutive leads and two different morphologic types of ST-depression.

UNLABELLED: We describe eight patients with a distinct electrocardiographic pattern of anterior wall myocardial infarction characterized by three main features: (1) a pattern of 'transmural ischemia' (ST-elevation with positive T-wave) in non-consecutive leads: a VL and V2, and two different types of ST-depression; (2) a pattern of 'true reciprocal changes' (ST-depression and negative T-wave) in III and a VF; (3) a pattern of 'sub-endocardial ischemia' (ST-depression with positive T-wave) in V4-5, while ST in V3 was either isoelectric or depressed. We characterize the electrocardiographic features and correlate them with the echocardiographic, radionuclide, and angiographic data. All patients admitted to the coronary care unit from January 1990 to April 1992 with evolving acute myocardial infarction were evaluated prospectively. Patients whose admission electrocardiogram met the description above were included. The electrocardiographic evolution, echocardiographic, Technetium MIBI tomography, and coronary angiography are described. Of 471 patients with acute anterior wall myocardial infarction, admitted to the coronary care unit during the study period, eight patients met the inclusion criteria (1.7% of acute anterior wall myocardial infarction). Echocardiographic studies revealed mid-anterior hypokinesis in two patients, anterior and apical hypokinesis in one, and no wall motion abnormality in four patients. Technetium MIBI tomography, done in five patients, was consistent with mid-anterior or midanterolateral infarction without involvement of the septum or apex. Coronary angiography, performed in seven patients, demonstrated significant obstruction of the first diagonal branch in all of the patients. In four patients, the diagonal occlusion was the only significant coronary lesion in the left coronary artery. CONCLUSION: Most of the anterior myocardial infarctions also involve the septal and apical regions. Anterior wall myocardial infarctions limited to the mid-anterior or mid-anterolateral wall, without apical or septal wall involvement are relatively rare. This study describes a special electrocardiographic form of anterior wall acute myocardial infarction. This distinct electrocardiographic pattern represents true mid-anterior wall myocardial infarction, caused by occlusion of a first diagonal branch of the left anterior descending coronary artery. The septal and apical regions are not involved because the blood supply via the left anterior descending artery is not interrupted.

Coronary Angiography↗

Spontaneous hemarthrosis following thrombolytic therapy for acute myocardial infarction.

We describe a 45-year-old man who developed a spontaneous hemarthrosis of his right knee following thrombolytic therapy with streptokinase and rtPA for acute myocardial infarction. Surprisingly, despite the wide use of thrombolytic therapy, only four cases of spontaneous hemarthrosis following thrombolysis have been previously reported. Prompt aspiration of the joint, after stopping anticoagulant therapy, and splinting will provide early diagnosis and may prevent further damage to the joint.

Blood Coagulation Tests↗

Bundle-branch reentry tachycardia.

A 21-year-old man with aborted sudden death developed bundle-branch reentry tachycardia at electrophysiologic study. Ablation of the right bundle branch was performed in an attempt to eliminate the recurrence of ventricular arrhythmia. The clinical arrhythmia was no longer inducible; however, a second type of ventricular tachycardia of a different mechanism and origin was induced. Following a new clinical episode of ventricular tachycardia with hemodynamic deterioration, an automatic implantable cardioverter and defibrillator was implanted.

Adult↗

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)

Adult↗

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).

Aged↗