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Biomedical subjects

M S Gotsman

Publications and source records attributed to M S Gotsman.

At least 127 records · Page 7Linked to original sources
PubMed1987

Prediction of atrial and ventricular fibrillation complicating myocardial infarction from admission data: a prospective study.

This study set out to examine prospectively two logistic formulae based on admission clinical data to predict ventricular or atrial fibrillation complicating acute myocardial infarction. A prospective study of 87 consecutive patients with acute transmural myocardial infarction was conducted. The formula for predicting ventricular fibrillation from the diastolic blood pressure, degree of ST-segment elevation, and QTc had a sensitivity of 93%, specificity of 83%, and a predictive value for an abnormal test of 62% (13 of 14 patients who developed ventricular fibrillation were identified). The formula for predicting atrial fibrillation from the age of the patient, a history of heart failure, systolic blood pressure, and four electrocardiographic parameters had a sensitivity of 78%, specificity of 85%, and a predictive value of 67% (14 of 18 patients identified). Our study shows that patients with myocardial infarction who are liable to develop ventricular or atrial fibrillation can be identified on admission from simple clinical data.

Atrial Fibrillation↗
PubMed1987

Accessory atrioventricular pathway, supra-, and infrahisian conduction impaired due to mitral annulus calcification.

Disorders of conduction occurring simultaneously in both normal and accessory pathways of patients with Wolff-Parkinson-White (WPW) syndrome have only rarely been observed. To our knowledge this is the first report of impaired conduction in both pathways in WPW syndrome due to mitral annulus calcification (MAC). This case of WPW syndrome type A presented the following conduction abnormalities: (1) right bundle-branch block; (2) transient second-degree AV block with prolonged PR interval of the conducted beats; (3) during electrophysiological study, induction of tachycardia, dependent (phase 3) second-degree AV block, and occasionally conduction of two consecutive beats, the second showing an increased H-V interval (from 25 to 60 ms) and left bundle-branch block (LBBB) pattern, due to (4) infrahisian conduction abnormality.

Aged↗
PubMed1987

Left ventricular function during physiological cardiac pacing: relation to rate, pacing mode, and underlying myocardial disease.

The hemodynamic effects of cardiac pacing at different rates and in different modes were studied in 21 patients who were candidates for permanent pacemaker implantation. Nine of these had primary conduction disturbances (PCD), ten had ischemic heart disease (IHD), seven with additional cardiac failure (CHF), and two had hypertrophic cardiomyopathy (HCM). In patients with PCD, atrial (AOO) and AV sequential (DVI) pacing did not change systolic blood pressure and pulse pressure but ventricular (VVI) pacing caused a progressive fall in these measurements, especially as heart rate increased. Ventricular volume and stroke volume (counts) derived from radionuclide ventriculography (RVG) decreased progressively with higher pacing rates, especially during VVI pacing. Cardiac output was maintained during VVI pacing by the increase in heart rate; during AOO and DVI pacing, cardiac output increased. Similar but more marked differences were observed in patients with IHD and CHF and the changes were even greater in the patients with HCM. Left ventricular (LV) ejection fraction changed little with increasing heart rate in PCD but decreased progressively with the onset of ischemia in IHD and CHF. There was no difference in ejection fraction in the different pacing modes. Graphs related to LV contractility (end-systolic pressure-volume relations) showed that AOO pacing produced the highest and VVI pacing produced the lowest curves of myocardial contractility in all patient groups, except that at higher rates the AOO curve shifted down again in patients with IHD and CHF, presumably with the onset of myocardial ischemia. This study showed that physiological pacing produced the best hemodynamic results in all patient groups. Higher pacing rates should be avoided in patients with ischemic heart disease while VVI pacing should not be used in patients with HCM. Blood pressure and RVG studies during temporary pacing are useful in selecting the optimal pacing system in an individual patient when the clinical choice is not clear.

Bradycardia↗
PubMed1987

Physiological changes induced in cardiac myocytes by cytotoxic T lymphocytes.

The "lethal hit" induced by viral specific, sensitized, cytotoxic T lymphocytes (CTL) attacking virus-infected heart cells is important in the pathogenesis of viral myocarditis and reflects the key role of CTL in this immune response. The mechanisms involved are incompletely understood. Studies of the physiological changes induced in mengovirus-infected, cultured, neonatal, rat heart cells by CTL that had been previously sensitized by the same virus are presented. The CTL were obtained from spleens of mengovirus-infected, major histocompatibility complex (MHC) matched adult rats. Cell wall motion was measured by an optical method, action potentials with intracellular microelectrodes, and total exchangeable calcium content by 45Ca tracer measurements after loading the myocytes with 45Ca and then exposing them to CTL. After 50 min (mean time) of exposing mengovirus-infected myocytes to the CTL, the mechanical relaxation of the myocyte was slowed, with a subsequent slowing of beating rate and a reduced amplitude of contraction. Impaired relaxation progressed, and prolonged oscillatory contractions lasting up to several seconds appeared, with accompanying oscillations in the prolonged plateau phase of the action potentials. Arrest of the myocyte contractions appeared 98 min (mean time) after exposure to CTL. These changes in action potentials and contractions were reversible either by washout with the normal medium or by the addition of verapamil. The amount of total exchangeable calcium in the cultured myocytes, 1 h after exposure to CTL, was significantly increased. This increase was prevented by pretreatment with verapamil. (ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Left ventricular function from end-systolic stress-shortening relations in mitral valve prolapse.

Left ventricular (LV) function was studied from end-systolic stress-shortening relations in 13 patients with mitral valve prolapse (MVP). Studies were made noninvasively using M-mode echocardiography with blood pressure measurements on the right arm from a Baumanometer cuff. Fifteen age and sex-matched normal subjects formed the control group. LV end-diastolic dimension was normal in MVP, while shortening fraction (p less than 0.05) and velocity of circumferential fiber shortening (mean Vcf) in the short axis of the ventricle were increased (p less than 0.05). Ventricular afterload, as measured by meridional end-systolic stress was reduced in MVP (p less than 0.01) but the slope of the stress-shortening curve was not different form normal. The decrease in end-systolic stress was related to the severity of prolapse (r = 0.63, p less than 0.05). The study implied that mid- or basal LV contractility was normal in MVP. The increased shortening fraction of the LV minor axis was in keeping with geometrical changes and a reduced ventricular afterload.

Adolescent↗
PubMed1987

Quantitation of variations in regional left ventricular function in isolated disease of the left anterior descending coronary artery.

The pattern of contraction of the endocardial wall of the left ventricle in the right anterior oblique cineangiogram was studied by using a frame by frame radial technique and a fixed centroid without correction for rotation and translation motion during the cardiac cycle. Spatial defects of contraction were quantitated by measuring the shortening fraction of each radius and temporospatial defects by using a time-contraction integral. Twelve normal subjects were used as a basis for comparison. Thirty-two patients with isolated disease of the left anterior descending (LAD) coronary artery were divided into seven arbitrary clinicopathological subsets. Five subsets showed significant quantitative differences in contraction from the normal subjects but there was no significant difference between the subsets. They had a typical defect of contraction in the distal two thirds of the anterior wall, the apex and distal quarter of the inferior wall of the left ventricle. The subsets included: (1) patients who had undergone an anterior myocardial infarction and who had total occlusion of the LAD artery and a large anterior infarction on ECG; (2) patients with a previous classical myocardial infarction but with only 95% residual narrowing of the LAD; (3) patients with an anterior infarction and total occlusion of the LAD with return of the R waves in the anterior precordial leads; (4) patients with anterior infarction, LAD obstruction and left bundle branch block and (5) patients with anterior infarction but with early successful reperfusion with intracoronary streptokinase. Two other subsets, (1) patients with total obstruction of the LAD without a clinical myocardial infarction or (2) subtotal occlusion of the LAD without infarction, had mild left ventricular dysfunction at rest and did not differ significantly from normal.

Adult↗
PubMed1987

Prehospital coronary thrombolysis. A new strategy in acute myocardial infarction.

Thirty-four patients with acute myocardial infarction were treated prospectively using a new strategy of prehospital intravenous streptokinase given by a physician-operated mobile intensive care unit. The 29 prehospital-treated patients who had experienced no previous myocardial infarction were compared to a similar group treated with streptokinase inhospital. Patients receiving streptokinase in the prehospital phase of acute myocardial infarction had smaller infarcts and better residual myocardial function than the group given streptokinase inhospital in terms of peak creatinine phosphokinase, ejection fraction, computer-derived dysfunction index, and electrocardiographic QRS score. The only difference between these groups at baseline was the duration of pain prior to initiation of streptokinase therapy. There were no major complications related to prehospital administration of streptokinase.

Aged↗
PubMed1987

Benefit of the steroid electrode.

A permanent pacemaker was implanted in an 80-year-old patient with complete heart block. The electrode had to be changed six times (endocardial, five and epicardial, one) due to a progressive rise in threshold with recurrent exit block. A porous, steroid eluting, endocardial electrode was implanted and has given 27 months of excellent service. This lead may be ideal for patients who have a progressive increase in threshold after repeated electrode implantation.

Aged↗
PubMed1987

Fat-free diet and myocardial excitability, refractoriness and ventricular fibrillation.

The lipid composition of the sarcolemma influences its function. The purpose of this study is to investigate the electrophysiological alterations induced in the rat's heart by dietary manipulation of cardiac fatty-acid composition. Strength-duration and strength-interval relationships were used to study excitability and refractoriness respectively. Ventricular fibrillation threshold measured by short bursts of rapid stimulation was used to indicate ventricular vulnerability. Gas liquid chromatography was used to analyse cardiac fatty-acid-composition. We used two-week-old rats fed with fat-free diet and 5% and 10% soya bean oil-supplemented diets for 6-9 weeks. Fat-free diet only was associated with increased eicosatrienoic acid content, a marker of essential fatty-acid deficiency. A decrease in poly-unsaturated to saturated (P:S) fatty-acid ratio was also observed. Five percent oil supplementation was associated with a delay and attenuation of this effect. Fat-free diet was associated with increased excitability, decreased refractoriness and reduced ventricular fibrillation threshold. Ten percent oil supplementation prevented these effects while 5% oil supplementation had only a temporary protective effect. We conclude that manipulation of dietary fat content can affect cardiac fatty-acid composition and electrophysiology.

Animals↗
PubMed1987

Influence of vessel involvement and early streptokinase therapy on regional and global left ventricular function in acute myocardial infarction.

150 consecutive patients with acute myocardial infarction received 750,000 units of intravenous streptokinase within four hours of pain onset. Angiography was performed on day 6, from which ejection fraction (EF), infarct-related ejection fraction (IREF), and non-infarct related ejection fraction (NREF) were calculated. 50% stenosis was considered to be significant. The streptokinase patients with patent infarct-related arteries who had no evidence of previous myocardial infarction were compared with 82 conventionally treated (without streptokinase) patients who had no evidence of previous myocardial infarction. Sub-group analysis based on vessel involvement, usage and timing of streptokinase was done. Streptokinase was associated with better left ventricular function in all sub-groups if given less than 2 hours after pain onset. In inferior myocardial infarction, streptokinase patients with single-vessel disease had normal EF (67 +/- 8), compared to significantly depressed EF in multi-vessel disease (56 +/- 12, p less than 0.05). This difference is accounted for more by the NREF than the IREF. In anterior infarction, patients with single-vessel disease did only slightly better than multi-vessel disease. In multi- and single-vessel anterior infarction, preservation of function by streptokinase appears to be due to the compensatory ability of the non-infarcted region as well as the residual function of the infarct-related region. region.

Cardiac Output↗
PubMed1987

Dietary lipid intake and myocardial electrophysiology.

We studied the effect of a fat-free diet on the cardiac electrophysiology of rats. Fourteen 2-week-old rats were maintained on a fat-free diet and 12 rats had a 5% soybean oil supplement to their diet. The rats were killed after 6 weeks and the hearts mounted on a Langendorff chamber. Atrioventricular (A-V) block was induced. Myocardial strength-duration (S-D) and strength-interval (S-I) curves were determined. A significant depletion of linoleic acid and elevation of palmitoleic, stearic, and oleic acids was found in the hearts obtained from rats on fat-free diet as compared with the hearts obtained from the rats on oil-supplemented diets. Hearts obtained from rats who had had the oil supplement had a shorter refractory period and an increased threshold for excitation; therefore, these hearts should be less vulnerable to cardiac dysrhythmias. Both S-D and S-I curves best fitted a logarithmic relationship. The intercepts and slopes of these curves were significantly different in the two groups. There were significant correlations between myocardial fatty acid composition (stearate and linoleate in particular) and the different electrophysiological parameters.

Animals↗
PubMed1987

Peripheral vascular disease in a middle-aged population sample. The Jerusalem Lipid Research Clinic Prevalence Study.

Peripheral artery status and prevalence of peripheral vascular disease were studied in a sample of 1,036 men and 556 women, residents of Jerusalem. Ankle blood pressures determined by the Doppler ultrasound technique (Parks Electronic Lab, USA), were higher in men than in women and increased with age. In a multivariable regression analysis, systolic blood pressure and plasma cholesterol levels were significantly and inversely related to the ankle/arm blood pressure in men, and alcohol intake was inversely associated in women. The prevalence of peripheral vascular disease, as determined by symptoms of intermittent claudication, was 1.3% in men and 1.8% in women; absent pedal pulses were found in 1.1% of the men and in 2.0% of the women; leg pain on the treadmill was a reason for termination of exercise in 3.7% of the men and in 5.4% of the women and an ankle/arm blood pressure ratio of less than 0.90 in 4.2% of the men and in 5.4% of the women. The overlapping of the diagnostic criteria was low. No consistent determinants of the various measures of peripheral vascular status were found. In multivariable logistic models, cigarette smoking was significantly associated with intermittent claudication [Odd ratio (OR) = 3.03, 95% confidence interval (CI) 1.27 to 7.26], age was associated with leg pain on the treadmill (OR = 1.91, 95% CI 1.08 to 3.40 in men and OR 3.52, 95% CI 1.52 to 8.16 in women), body mass index was associated with absent and diminished pulses in women (OR = 1.61, 95% CI 1.07 to 2.42, systolic blood pressure was associated with an ankle/arm ratio of less than 0.90 in men (OR = 1.35, 95% CI 1.01 to 1.81), and glucose was associated with absent and diminished pulses in women (OR = 1.20, 95% CI 1.00 to 1.44).

Adult↗
PubMed1986

Importance of early initiation of intravenous streptokinase therapy for acute myocardial infarction.

The importance of timing of intravenous streptokinase (SK) administration in patients with acute myocardial infarction (AMI) was evaluated. Intravenous SK, 750,000 U, was administered within 4 hours of the onset of ischemic chest pain to 72 consecutive patients having their first AMI. Six days later, cardiac catheterization was performed to calculate global ejection fraction (EF), and computer-derived infarct-related regional EF and dysfunction index were also determined; electrocardiograms were recorded, from which QRS scores could be calculated to estimate infarct size. Of 19 patients who had an anterior AMI, 12 (63%) who received intravenous SK within 2 hours after onset of pain sustained only minimal damage in terms of global EF, infarct-related EF, dysfunction index and QRS score. All 10 patients who received SK 2 to 4 hours after pain onset had large infarcts (p less than 0.001). Of the former group, 11 of 12 patients (91%) whose pain was relieved within 1.5 hours of intravenous SK administration (presumably due to successful reperfusion) had a good outcome, whereas all 7 whose pain lasted longer did poorly (p less than 0.001). Furthermore, among patients with anterior AMI, 11 of 14 (79%) whose pain was relieved within 3.5 hours of onset had small infarcts, compared with none of the 12 patients whose pain lasted longer (p less than 0.0001). In inferior AMI, the critical time between onset of pain and initiation of intravenous SK was 1.5 hours (p less than 0.05). The timing of initiation of thrombolytic therapy and the total pain duration are critical in determining outcome in AMI, and time intervals vary depending on infarct localization.

Aged↗
PubMed1986

Short-term effect of nifedipine on effort tolerance in patients with angina pectoris.

The short-term effect of oral nifedipine on effort tolerance was tested in 10 patients with effort angina pectoris and a positive effort test (GXT). The patients had four symptom-limited GXTs, using the Bruce protocol, on each day of the study at 0800, 1000, 1400, and 1800 hours. They received four doses of 10 mg oral nifedipine on one day and four doses of placebo on the other, each dose given half an hour prior to each GXT. Values with nifedipine were compared to values with placebo at the same time during each day. Nifedipine improved effort tolerance by 0.5 +/- 0.6 min (p = NS) on the first GXT (mean +/- SEM), by 1.2 +/- 0.6 min (p = NS) on the second GXT, by 1.0 +/- 0.3 min (p less than 0.01) on third GXT, and by 1.3 +/- 0.3 min (p less than 0.01) on the fourth GXT. Improvement of effort tolerance was associated with a fall in resting blood pressure and less ST depression; these changes were statistically significant only on the fourth GXT, which may indicate a cumulative effect of subsequent doses of nifedipine.

Administration, Oral↗
PubMed1986

Radionuclide left ventricular function curve during atrial pacing in normal subjects and in patients with coronary artery disease.

We used radionuclide angiography during right atrial pacing to assess left ventricular function in 7 normal subjects and 20 patients with coronary artery disease. A left ventricular function curve relating stroke volume to end-diastolic volume was plotted for each patient. The normal pacing ventricular function curve was a straight line passing through the origin of axes. The pacing ventricular function curve was abnormal in 18 of the 20 patients with coronary artery disease, and three different shaped curves were obtained, reflecting decreased contractile force for the same end-diastolic volume during ischemia. Cardiac output and blood pressure do not change during atrial pacing, thus the Frank-Starling relationship is evaluated by this method during almost experimentally controlled conditions. Relating stroke volume to end-diastolic volume, and not end-diastolic pressure, distinguishes between overall left ventricular systolic function and left ventricular compliance.

Adult↗
PubMed1986

Bradycardia and hypotension following reperfusion with streptokinase (Bezold-Jarisch reflex): a sign of coronary thrombolysis and myocardial salvage.

Acute myocardial infarction, particularly of the inferior wall, is frequently associated with bradycardia and hypotension. This study reports the occurrence of transient bradycardia hypotension (TBH) (Bezold-Jarisch reflex) following thrombolytic therapy with intravenous streptokinase. Of the 52 patients, 42 had successful reperfusion, and 12 of the latter developed reflex TBH. The Bezold-Jarisch reflex occurred in 10 of 24 patients with inferior wall acute myocardial infarction and in 2 of 28 patients with anterior wall infarction (p less than 0.05). The reflex was associated with significantly more non-Q wave infarctions (p less than 0.05) and also with reduction of left ventricular damage, as evidenced by a lower QRS score (4 +/- 3.8 vs 8.9 +/- 5.6, p less than 0.01) and a higher ejection fraction (61 +/- 13% vs 49 +/- 16%, p less than 0.05). Patients with inferior wall acute myocardial infarction were divided into those with TBH (10 patients) and those without TBH (14 patients). TBH was associated with a significantly higher infarct-related regional ejection fraction (60 +/- 19% vs 35 +/- 18%, p less than 0.05). The results of this study confirm previous findings that reperfusion of the inferoposterior myocardium is capable of stimulating reflex TBH. Furthermore, TBH is associated with patency of infarct-related coronary arteries and myocardial salvage.

Adult↗