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Biomedical subjects

B Strasberg

Publications and source records attributed to B Strasberg.

At least 91 records · Page 5Linked to original sources

[Classification of acute myocardial ischemia by electrocardiography].

Electrocardiographic recording during chest pain is usually performed for detection of myocardial ischemia and localization of the affected area. By analyzing changes in electrocardiograms recorded during chest pain, pathophysiological mechanisms of ischemia, prediction of coronary pathology, and the risk of evolution to myocardial infarction can be determined. Myocardial ischemia is caused by either an increase in O2 demand, reduction in coronary flow, or both. The former is manifested by tachycardia and in such patients measures should be taken to slow the heart rate. Patients with ischemia without tachycardia suffer from reduction of coronary flow and therapy should be aimed at increasing flow. We classify patients with ischemia but without tachycardia according to electrocardiographic patterns recorded during chest pain by precordial leads as follows: group 1, those with ST segment elevation and with positive T waves; group 2, ST segment depression and negative T waves; and group 3, ST depression and positive T waves. Group 1 patients have anterior wall ischemia and the left anterior descending artery is usually involved. They are possible candidates for coronary angiography. In group 2, the electrocardiographic changes reflect extensive subendocardial myocardial ischemia. We found severe coronary artery disease (LMCA or right main artery equivalent) in 69% of such patients, and the mortality in those with subsequent myocardial infarction was 77%, mainly due to pump failure. When this latter electrocardiographic pattern is found, intervention should be prompt, and surgery rather than angioplasty is usually necessary. Patients with ischemic ST depression maximal in V2-V3 should not be included in this group since these changes are reciprocal with posterolateral wall ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

Deleterious effects of intravenous verapamil in Wolff-Parkinson-White patients and atrial fibrillation.

Three patients presented to the emergency room with atrial fibrillation and fast ventricular response with wide preexcited QRS complexes (Wolff-Parkinson-White syndrome). All three patients received intravenous verapamil (5-10 mg). The first patient developed ventricular fibrillation requiring several defibrillations; the second patient developed severe hemodynamic deterioration requiring urgent cardioversion; in the third patient a marked increment in the ventricular response was noted, however, there was no hemodynamic impairment. Verapamil may cause detrimental results when given to patients with the Wolff-Parkinson-White syndrome and atrial fibrillation. Its administration should therefore be considered as an absolute contraindication in these patients.

Adult↗

The head-up tilt table test in patients with syncope of unknown origin.

Forty patients with recurrent syncopal episodes of uncertain etiology were evaluated with a 60-degree head-up tilt table test for 60 minutes. There were 21 men and 19 women, with a mean age of 36 +/- 19 years, a mean of 7.6 syncopal episodes per patient, and a mean duration of symptoms of 4.2 +/- 6 years. Twelve patients had evidence of organic heart disease. Ten control subjects with no history of syncope were studied similarly. Syncope did not occur in any of these controls. Syncope occurred in 15 patients (37.5%) after a mean standing time of 42 +/- 12 minutes. Syncope was due to a typical vasovagal reaction in 11 patients and to hyperventilation in three patients. One last patient fainted without changes in heart rate or blood pressure. In each case, symptoms during the test resembled those previously experienced.

Adolescent↗

The noninvasive evaluation of syncope of suspected cardiovascular origin.

We have reviewed all available noninvasive diagnostic studies for the evaluation of syncope of suspected cardiovascular origin. This eight-step diagnostic approach covers the majority of available syncopal etiologies. In patients evaluated for syncope, we believe a complete noninvasive evaluation should be performed (if clinically indicated) before performing invasive electrophysiologic studies.

Cardiovascular Diseases↗

Head-up tilt table evaluation in a trained athlete with recurrent vaso-vagal syncope.

A 27-year-old trained athlete with recurrent syncope of suspected vaso-vagal origin was evaluated. A 60 degrees head-up tilt table test reproducibly triggered the patient's spontaneous symptoms and allowed the investigation of different modalities of therapy (medical and pacing) in preventing syncopal episodes. The head-up tilt table test may be a useful tool in the evaluation of syncope of vaso-vagal origin, helping to determine the initial precipitating vagal event and the effect of therapy.

Adult↗

Acute anterior wall myocardial infarction presenting with positive T waves and without ST segment shift. Electrocardiographic features and angiographic correlation.

Eighteen patients with a first AMI, who during the acute ischemic phase did not develop ST segment elevation, but only positive or peaked T waves, are described. Patients who do not develop ST segment elevation during evolving anterior AMI represent a subgroup with a high probability of total obstruction of the LAD artery with retrograde filling via collateral vessels and a small degree of left ventricular dysfunction. We assume that during the period of total obstruction there was preexisting adequate collateral circulation in order to prevent transmural ischemia, which explains the absence of ST segment elevation.

Adult↗

Surgical removal of echocardiographically detected multiple pedunculated and mobile left ventricular thrombi in acute myocardial infarction.

Two-dimensional echocardiography revealed at least three left ventricular mural thrombi in a 59-year-old man with acute anterior myocardial infarction. The thrombi, which had highly mobile pedunculated elements, were attached to the septo-apical wall and protruded into the left ventricular cavity. In spite of the lack of a clinical event but in view of the potential risk of embolization, surgical removal of the thrombi was performed on the 16th day of hospitalization.

Echocardiography↗

Effects of isosorbide dinitrates intravenously in high doses over a short period in anterior acute myocardial infarction.

The effects of intravenous isosorbide dinitrate administered in high doses over a short period of time in 17 patients (14 men, 3 women, mean age 67 years) with anterior wall acute myocardial infarction were evaluated. Patients were classified into 2 groups based on the electrocardiographic pattern of acute ischemia. Patients presented with anterior acute myocardial infarction; an electrocardiographic pattern of third-degree ischemia demonstrated a more favorable electrocardiographic and radionuclear angiographic evolution than similar patients who presented with an electrocardiographic pattern of second-degree ischemia.

Adult↗

Ischemic blocks during early phase of anterior myocardial infarction: correlation with ST-segment shift.

Of 760 consecutive cases with anterior acute myocardial infarction (AMI), 55 developed acute bundle-branch block (BBB), fascicular block, or high-degree atrioventricular block during the hyperacute ECG stage of AMI. According to the direction of the ST segment during the acute ischemic episode, patients were divided into two groups. Group A consisted of 32 patients who developed BBB during ST-segment elevation, positive T wave, and absent or minimal Q wave. Group B consisted of 23 patients who developed BBB during ST-segment depression and evolved into anterior AMI. Group A was characterized by a higher incidence of right BBB and left anterior hemiblock [91% vs. 26% and 56% vs. 13%, respectively (p less than 0.005)]. Group B was characterized by a higher incidence of left BBB and left posterior hemiblock [57% vs. 9% and 26% vs. 12%, respectively (p less than 0.001)]. The BBB was transient (disappearing within hours to one day) in 14 patients in Group A and in 5 patients in Group B. The incidence of progression to high-degree atrioventricular block was almost equal in the two groups (25% and 26%). The mortality rate was very high in both groups, but higher in Group B [74% vs. 59% (p = NS)] especially in those with LBBB (85%). Most patients died on the day of occurrence of BBB [Group A, 50% vs. Group B, 70% (p = NS)]. The causes of death in both groups were cardiogenic shock and/or electromechanical dissociation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Unstable angina: ST segment depression with positive versus negative T wave deflections--clinical course, ECG evolution, and angiographic correlation.

Thirty-two consecutive patients who initially had horizontal or downward-sloping ST segment depression confined to the precordial leads were studied. Patients were divided into two groups: group A included 21 patients with horizontal or downward-sloping ST depression with peaked positive T waves, and group B comprised 11 patients with peaked negative T waves and downward or horizontal ST depression. The incidence of acute myocardial infarction (AMI) was similar (group A 38.1% vs group B 36.4%; p greater than 0.05). In-hospital mortality was much more significant in group B (p = 0.03). Coronary arteriography was performed in 31 patients. Of the 10 patients in group B who were catheterized, seven (70%) had left main occlusion. Of the 21 patients in group A, none had a significant left main lesion (p = 0.001), although eight (38.1%) had single-vessel disease (p = 0.05). Thus the ECG pattern of horizontal or downward-sloping ST depression passing into a peaked negative T wave identifies a subgroup of high-risk patients in whom the prognosis is poor once AMI occurs. Early catheterization is recommended when this ischemic pattern is apparent on the ECG.

Aged↗

Surgical removal of a mobile, pedunculated left ventricular thrombus: report of 4 cases.

During an 11-month period, 4 patients underwent surgical removal of a mobile, pedunculated left ventricular thrombus. All 4 patients had a history of myocardial infarction. Two of the 4 patients had systemic emboli, and in the 2 others, the ventricular thrombi were removed to prevent emboli. The thrombus was removed during the acute phase of myocardial infarction in 2 patients and one and two years, respectively, following the infarct in the remaining 2 patients. Concomitant coronary artery bypass grafting was performed in 3 patients. There were no early or late deaths, and none of the patients had clinical or echocardiographic evidence of recurrent thrombi or emboli at follow-up 3 to 15 months later. These results indicate that left ventricular thrombectomy might be an effective treatment for patients with mobile, pedunculated, left ventricular thrombi. However, additional experience is required to compare surgical and medical treatment.

Aged↗

Ventricular fibrillation in a patient with 'silent' mitral valve prolapse.

A patient with clinically silent mitral valve prolapse experienced an episode of out-of-hospital cardiac arrest due to ventricular fibrillation. This arrhythmia was easily replicated in the electrophysiology laboratory and despite treatment with amiodarone alone and amiodarone in combination with propranolol. Amiodarone in combination with quinidine prevented the induction of ventricular fibrillation and proved effective during a 3-year follow-up period. Even though a clear-cut relationship between the arrhythmias and mitral valve prolapse cannot be established, this case suggests that sudden death can occur in patients with mitral valve prolapse but without the known risk factors for the development of sudden death.

Adult↗

Ventricular fibrillation complicating acute myocardial infarction. Two distinct clinical and electrocardiographic features.

Two distinct electrocardiographic patterns of ventricular fibrillation (VF) complicating acute myocardial infarction (AMI) were observed in 34 patients during the first 24 hours from initial symptoms. Type 1 (seven patients) was characterized by fast disorganized ventricular activity, small voltage, and no clear identifiable QRS complexes (fine VF). Type 2 (27 patients) was defined as multiform QRS configuration (greater than 300/min) with marked changes in the amplitude (polymorphous VF). Type 1 rhythm was seen mostly during the hyperacute ischemic phase, probably associated with total coronary vessel occlusion; type 2 was observed when Q waves were already present in the electrocardiogram.

Adult↗