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Biomedical subjects

B Strasberg

Publications and source records attributed to B Strasberg.

At least 37 records · Page 2Linked to original sources
PubMed1999

Acute myocardial infarction following sildenafil citrate (Viagra) intake in a nitrate-free patient.

Since its introduction to the market in March 1997, sildenafil acetate (Viagra) has been prescribed to 1.7 million people. Sixteen men who were taking the drug have died, 7 of them during or soon after sexual activity. Most of these data have been derived from the media and not from the scientific literature. There is a general impression that cardiovascular complications of sildenafil occur mainly when the drug is taken concomitantly with nitrates. We describe a 65-year-old man with known coronary artery disease who had an acute myocardial infarction shortly after taking sildenafil and engaging an sexual activity. The patient had not been using nitrates. We suggest that the emotional arousal induced by Viagra, followed by the heavy physical exertion during sexual activity, triggers plaque rupture that leads to acute myocardial infarction.

Aged↗
PubMed1999

Relation between QT dispersion and slow intraventricular conduction in patients with acute anterior wall myocardial infarction.

BACKGROUND: QT dispersion has been proposed as a simple, noninvasive measure for identifying patients at risk of postinfarction arrhythmia. It is assumed to reflect nonuniform ventricular repolarization, which, in turn, may result from regional differences in repolarization time as well as from localized activation delay. The aim of this study was to examine the relation between QT dispersion and intraventricular conduction abnormalities in patients with acute anterior wall myocardial infarction. METHODS AND RESULTS: Standard 12-lead electrocardiographic and 12-lead signal-averaged electrocardiographic recordings were performed in 25 patients with a first Q-wave anterior wall myocardial infarction. Measures calculated by using the 6 precordial (V1 through V6) leads for QT dispersion were (1) difference between maximum and minimum QT and QTc intervals and (2) standard deviation of QT and QTc intervals. Measures calculated from the signal-averaged electrocardiogram were (1) maximum filtered QRS duration; (2) mean; and (3) standard deviation of filtered QRS duration. No relation was found between any measure of filtered QRS duration and that of QT dispersion by using linear correlation analysis. Similarly, no significant association was demonstrated between the filtered QRS duration and corresponding QT interval measurements (total 131 leads). CONCLUSIONS: The lack of correlation between signal-averaged electrocardiogram indexes of slow intraventricular conduction and electrocardiogram variables of QT dispersion suggests an independent predictive value for the 2 methods in identifying patients at risk of postinfarction arrhythmia. This suggestion is further supported by the finding that altered activation sequence is an unlikely mechanism of QT dispersion in patients with acute myocardial infarction, as indicated by the lack of association between the filtered QRS duration and corresponding QT interval measurements.

Arrhythmias, Cardiac↗
PubMed1999

Perforation of the right ventricular free wall by an active fixation transvenous cardioverter defibrillator lead.

A 58-year-old patient with dilated cardiomyopathy underwent implantable cardioverter defibrillator (ICD) implantation. The postoperative course was complicated by perforation of the right ventricular free wall by the active fixation transvenous ICD lead. The type of ICD lead and the type of organic heart disease are apparently important risk factors for perforation.

Cardiomyopathy, Dilated↗
PubMed1999

The prognostic implications of negative T waves in the leads with ST segment elevation on admission in acute myocardial infarction.

We assessed the prognostic significance of negative T waves on admission in leads with ST elevation in 2,853 patients with acute myocardial infarction treated with thrombolysis. Patients were classified into 2 groups based on the presence of negative (T-) or positive (T+) T waves in the leads with ST elevation on admission. T+ and T- waves on admission were detected in 2,601 (91%) and 252 (9%) patients, respectively. T- waves were observed in 6.7 and 9.6% of patients admitted </=2 and 2-6 h after onset of infarction, respectively. There was a difference in prognosis between patients admitted </=2 and >2 h after symptom onset. T- patients admitted </=2 h after onset had no hospital mortality (0/52 patients), as compared to a 5.0% mortality rate in T+ patients (36/726 patients; p = 0.19). T- patients treated >2 h after onset suffered higher mortality (20/196 patients; 10.2%) than T+ patients (100/1,836 patients; 5.4%; p = 0.01). Multivariate analysis of the data on patients treated >2 h after onset demonstrated T- waves to be associated with mortality (OR 1.86; 95% CI 1.07-3.25; p = 0.017). T- waves in leads with ST elevation upon admission are associated with adverse prognosis in patients presenting >2 h after symptom onset, whereas in patients presenting </=2 h after first symptoms, T- waves may be associated with better prognosis.

Diagnostic Tests, Routine↗
PubMed1998

QRS complex distortion predicts no reflow after emergency angioplasty in patients with anterior wall acute myocardial infarction.

BACKGROUND: In patients with acute myocardial infarction, distortion of the terminal portion of the QRS complex on the electrocardiogram (ECG) at the time of their admission to hospital is associated with larger final infarct size and greater mortality. This study assessed the results of emergency coronary angioplasty in patients with anterior acute myocardial infarction with and without distortion of the terminal portion of the QRS complex on the admission ECG. METHODS: We assessed the Thrombolysis in Myocardial Infarction (TIMI) trial flow grade, resolution of ischemic ECG changes, and clinical outcome after emergency angioplasty for acute anterior wall myocardial infarction in patients with (n = 21) and without (n = 21) distortion of the terminal portion of the QRS complex on the admission ECG. RESULTS: Compared with patients without distortion of the terminal portion of the QRS complex on the admission ECG, those with distortion had a significantly lower incidence of TIMI flow grade 3 (52% compared with 84%, P < 0.05), lower rate of resolution of the ischemic ECG changes (33% compared with 84%, P < 0.005), and greater rate of mortality during their stay in hospital despite successful balloon angioplasty (19% compared with 0%, P < 0.05). CONCLUSIONS: In patients with anterior wall acute myocardial infarction, distortion of the terminal portion of the QRS complex on the admission ECG predicts a greater mortality rate and a greater incidence of reflow impairment after emergency angioplasty.

Adult↗
PubMed1998

Are there differences among patients with inferior acute myocardial infarction with ST depression in leads V2 and V3 and positive versus negative T waves in these leads on admission?

We assessed whether there are differences among patients with inferior acute myocardial infarction and ST segment depression in leads V2-V3 between those with positive versus negative T waves on admission. We found no differences in the prevalence of concomitant significant left anterior descending coronary artery stenosis and anterior or posterior wall motion abnormalities on echocardiography between the two groups. Precordial ST segment depression with negative T wave may be the early electrocardiographic pattern of posterior infarction, reflecting ST segment elevation with positive T waves that would have been detected by leads facing the posterior wall.

Cohort Studies↗
PubMed1997

Importance of the conal branch of the right coronary artery in patients with acute anterior wall myocardial infarction: electrocardiographic and angiographic correlation.

OBJECTIVES: This study assessed prospectively the correlation between the conal branch of the right coronary artery and the pattern of ST segment elevation in leads V1 and V3R during anterior wall acute myocardial infarction (AMI). BACKGROUND: The traditional electrocardiographic (ECG) definition of anteroseptal AMI-ST segment elevation in leads V1 to V3-has recently been challenged. The significance of ST segment elevation in lead V1 during anterior wall AMI is unclear. METHODS: The admission 12-lead ECG with additional lead V3R and the coronary angiograms performed within 10 days of hospital admission were evaluated in 28 consecutive patients (mean age +/- SD 62 +/- 9 years) admitted to the coronary care unit with anterior wall AMI. Patients were classified into two groups according to the magnitude of ST segment elevation in lead V1: group A (elevation > or = 1.5 mm, n = 12) and group B (elevation < 1.5 mm, n = 16). Two types of conal branch were identified: small (not reaching the interventricular septum [IVS]) and large (reaching the IVS). RESULTS: ST segment elevation in lead V3R was found in 11 (92%) and 6 (37%) patients from group A and group B, respectively (p < 0.001); a small conal branch was seen in 10 (83%) and 3 (19%) patients, respectively (p < 0.001). Ten patients (all from group B) had a large conal branch. CONCLUSIONS: ST segment elevation in lead V1 in the admission ECG of patients with anterior wall AMI is strongly related to ST segment elevation in lead V3R and is associated with a small conal branch. Our findings suggest that lead V1 reflects the right paraseptal area supplied by the septal branches of the left anterior descending coronary artery (LAD), alone or together with the conal branch. The absence of ST segment elevation in lead V1 during anterior AMI suggests that the IVS is protected by a large conal branch in addition to the septal branches of the LAD (double circulation).

Adult↗
PubMed1997

Atrial natriuretic peptide levels after different types of inferior wall myocardial infarction.

BACKGROUND: Atrial natriuretic peptide (ANP) is released from cardiac atrium secondary to increased atrial pressure. The plasma levels of ANP have been found to be related to short- and long-term prognosis after acute myocardial infarction (MI). The purpose of the present study was to investigate the plasma levels of ANP in three groups of patients with inferior wall acute MI classified according to ST-segment depression in the precordial leads. METHODS: The study population consisted of 18 patients with inferior wall acute MI classified into three types: Type 1 = no precordial ST-segment depression (7 patients), Type 2 = 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 (4 patients), and Type 3 = maximal precordial ST-segment depression in leads V4 to V6 (7 patients). RESULTS: Radioimmunoassay showed that plasma ANP levels were significantly higher in patients with Type 3 acute inferior wall myocardial infarction compared with those with Types 1 and 2 (313.1 +/- 233, 73.0 +/- 27.5), and 84 +/- 32.7 pg/ml, respectively, p = 0.018). CONCLUSIONS: Plasma ANP levels are higher in patients with Type 3 acute inferior wall MI compared with patients with Types 1 and 2. These findings, together with earlier ones, may contribute to our understanding of the pathophysiology of the presence of ST-segment depression in the precordial leads in inferior wall acute MI.

Aged↗
PubMed1997

Isolated right ventricular infarction presenting as anterior wall myocardial infarction on electrocardiography.

Isolated right ventricle infarction is extremely rare, and its electrocardiographic (ECG) signs may be misinterpreted or even missed, especially when a typical clinical picture is lacking. This paper describes a case of isolated right ventricle infarction, recognized only by echocardiography. The patient presented with ST-segment elevation in left precordial leads together with minimal ST-segment elevation in inferior leads on a 12-lead ECG. Angiography revealed the culprit right coronary artery, which was small and nondominant. No significant obstructions were found in the left anterior descending artery. This case demonstrates that the ECG appearance of isolated right ventricle infarction may mimic anterior wall infarction and can be easily missed if not suspected.

Electrocardiography↗
PubMed1997

The relationship between the electrocardiographic pattern with TIMI flow class and ejection fraction in patients with a first acute anterior wall myocardial infarction.

AIMS: The aim of this study was to assess the value of the electrocardiogram in predicting the patency of the left anterior descending artery and left ventricular ejection fraction in patients with a first acute anterior wall myocardial infarction at discharge from the coronary care unit. METHOD: We included 116 consecutive patients with an acute anterior myocardial infarction who had undergone coronary angiography and left ventriculography before discharge from the coronary care unit (7th to 10th day). The ST segment, either elevated or isoelectric (< 1 mm), and the T wave (positive or negative) in precordial leads V2-V4 were analysed and compared to the TIMI flow from each patient. RESULTS: Out of 69 patients with negative T waves, 38 (55%) had TIMI flow 3 compared with 20 (29%) and 11 (16%) with TIMI flow 2 and 0-1, respectively; and out of 47 patients with positive T waves seven (15%) had TIMI flow 3, 17 (36%) TIMI flow 2 and 23 (49%) TIMI flow 0-1 (P < 0.001). Out of 63 patients with an isoelectric ST segment, 35 (55%) had TIMI flow 3, 18 (29%) TIMI flow 2 and 10 (16%) TIMI flow 0-1, and out of 53 with ST segment elevation, 10 (19%) had TIMI flow 3, 19 (36%) TIMI flow 2 and 24 (45%) TIMI flow 0-1 (P < 0.001). When both parameters were analysed together, we found that in 46 patients with both isoelectric ST segments and negative T waves, 30 (65%) had TIMI flow 3 compared with two of 30 (7%) patients with ST segment elevation and positive T waves (P < 0.001). Patients with isoelectric ST segments had a better degree of left ventricular ejection fraction (57.8 +/- 14.1%) than patients with ST segment elevation (41.7 +/- 13%) (P < 0.001). Patients with positive and negative T waves had a similar left ventricular ejection fraction (49 +/- 18.1% vs 51 +/- 14%). CONCLUSION: We concluded that patients with a first acute anterior myocardial infarction and an electrocardiogram pattern of an isoelectric ST segment and a negative T wave have a higher incidence of a patent left anterior descending coronary artery than similar patients with ST segment elevation and a positive T wave. An isoelectric ST segment is also related to better left ventricular function.

Cardiac Catheterization↗
PubMed1997

Implantation of cardioverter defibrillator and pacemaker using the same pectoral quadrant.

We implanted a cardioverter defibrillator (ICD) together with a pacemaker system in three patients with ventricular tachycardia and bradyarrhythmias. Both systems (ICD and pacemaker) were implanted in the same left pectoral quadrant using a single skin incision and the subclavian and/or the cephalic vein. The ICD was implanted deep to the pectoralis major muscle, the pacemaker was placed subcutaneously in a more medial pocket. There were no technical difficulties during implantation or complications during follow-up.

Aged↗
PubMed1997

Radiofrequency catheter ablation of ectopic atrial tachycardia.

Ectopic atrial tachycardia (EAT) is an uncommon type of supraventricular tachycardia. It is usually chronic, incessant and resistant to pharmacologic therapy. Radiofrequency catheter ablation, which has become one of the treatments of choice for the more common types of supraventricular tachycardia, has recently also been shown to be effective in EAT. Radiofrequency catheter ablation was attempted in three patients with incessant EAT. Two of the patients, aged 7 and 13 years, had signs of left ventricular dysfunction, and the EAT originated in the left atrium. The remaining patient, aged 72 years, had a right EAT with normal left ventricular function. Radiofrequency ablation was guided by endocardial atrial mapping to locate the site of earliest atrial activation. Ablation was successful in all three patients, with complete cure of the tachycardia for a follow-up period of 12 to 19 months. Radiofrequency catheter ablation of EAT is highly successful and should be considered as one of the treatments of choice for this arrhythmia.

Adolescent↗
PubMed1996

Exercise-induced syncope and Holter-documented asystole in an endurance runner with moderate aortic stenosis.

The case of an endurance runner with moderate aortic stenosis, who had recurrent syncope, is reported. A Holter recording during syncope revealed asystole lasting 57 s. Head-up tilt table test with isoproterenol was abnormal. No important abnormality was found in sinus or atrioventricular nodal functions. It was postulated that the syncope was due to exaggerated left ventricular baroreflex response, probably aggravated by the increased vagal tone in an endurance runner. The patient was given a beta-adrenergic blocker, and a pacemaker was implanted because of the profound cardio-inhibitory response. The arguments for this approach are discussed.

Adrenergic beta-Antagonists↗
PubMed1996

Relationship between late potentials and the predischarge electrocardiographic pattern in patients with acute anterior wall myocardial infarction.

HYPOTHESIS: The presence of late potentials on the signal-averaged electrocardiogram (SAECG) identifies patients at high risk for development of ventricular tachyarrhythmias after myocardial infarction (MI). METHODS: The electrocardiogram and left ventricular function in 65 patients recovering from a first acute anterior wall MI were analyzed. We compared the pattern of the ST segment (isoelectric or elevated) and of the T wave (positive or negative) with the SAECG using an orthogonal bipolar lead configuration (X, Y, Z) with bidirectional Butterworth filtering (Simson's method). RESULTS: Abnormal SAECG was found in 17 (26%) patients; 11 of 18 patients with ST elevation had abnormal SAECG, and only 6 of 47 patients with isoelectric ST segment developed abnormal SAECG (p < 0.0001, odds ratio = 10.74). Of 19 patients with positive T waves, 10 had abnormal SAECG, and abnormal SAECG was found in 7 of 46 patients with negative T waves (p < 0.003, odds ratio = 5.27). When both parameters were considered together, 9 of 12 patients with ST elevation and positive T wave developed abnormal SAECG, and 35 of 40 patients with isoelectric ST and negative T wave had normal SAECG (p < 0.0002). Left ventricular ejection fraction was similar in patients with abnormal SAECG (43 +/- 14%) and normal SAECG (46 +/- 11%). CONCLUSION: These findings suggest that patients with anterior wall MI and a predischarge pattern of ST elevation and positive T wave have a higher incidence of abnormal SAECG and therefore may have a worse prognosis, especially related to the subsequent development of ventricular arrhythmias.

Action Potentials↗
PubMed1996

Acute myocardial infarction entailing ST-segment elevation in lead aVL: electrocardiographic differentiation among occlusion of the left anterior descending, first diagonal, and first obtuse marginal coronary arteries.

Acute myocardial infarction with ST elevation in lead aVL may represent involvement of the first diagonal or the first obtuse marginal branch. This study assesses the correlation among different electrocardiographic patterns of acute myocardial infarction with ST elevation in aVL and the site of the infarct-related artery occlusion. Patients who underwent coronary angiography within 14 days of infarction with an unequivocal culprit lesion were included. Fifty-seven patients were evaluated. The culprit lesion was in the left anterior descending coronary artery proximal to the first diagonal, first diagonal, and first obtuse marginal branches, in 38, 8, and 11 patients, respectively. ST elevation in aVL and V2 through V5 signifies left anterior descending artery occlusion proximal to the first diagonal branch (positive predictive value [PPV] and negative predictive value [NPV] of 95% and 94%, respectively). ST elevation in aVL and V2, not accompanied by ST elevation in V3 through V5, favors occlusion of the first diagonal branch (PPV, 89%; NPV, 100%). ST elevation in aVL accompanied by ST depression in V2 predicts obstruction of the first obtuse marginal branch (PPV, 100%; NPV, 98%).

Cineradiography↗