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Biomedical subjects

E Ben-Ari

Publications and source records attributed to E Ben-Ari.

At least 19 recordsLinked to original sources
PubMed1993

Left ventricular dynamics during strenuous isometric exercise in marathon runners, weight lifters and healthy sedentary men: comparative echocardiographic study.

Global and segmental left ventricular dynamics during strenuous large-muscle isometric exercise were compared between endurance and static type professional athletes and sedentary men. Using a trunk dynamometer and supine echocardiography, only the weight lifters manifested increased (p < 0.01) wall thickness during both diastole and systole, resulting in decreased left ventricular volume at end systole. These group-related differences would suggest a causal relationship between chronic intensive weight-lifting training and efficient myocardial dynamics at the time of strenuous isometric exercise.

Adult↗
PubMed1992

Usefulness of heavy isometric exercise echocardiography for assessing left ventricular wall motion patterns late (> or = 6 months) after acute myocardial infarction.

The aim of this prospective study was to determine the effects of heavy isometric exercise on left ventricular (LV) wall motion patterns in patients who have had myocardial infarction, and to compare heavy isometric exercise with dynamic exercise for competence in eliciting LV wall motion abnormalities at equivalent rate-pressure products. Echocardiography was performed in 42 patients during supine bicycle ergometry and during heavy dynamometer stretching at 50% of maximal voluntary contraction. Systemic vascular resistance increased from 1,484 to 1,649 dynes s cm-5 (p < 0.05) during isometric exercise, and decreased significantly during dynamic exercise. Wall motion abnormalities or new asynergy were induced by isometric exercise in 120 segments, 107 of which (89%) showed significant stenosis of the perfusing coronary artery. Hypokinesia was the dominant pattern in the range of 76 to 90% narrowing; akinesia was dominant at 91 to 100% narrowing. Wall motion abnormalities were also documented in 13 segments (11%) assumed to be supplied by vessels with nonsignificant stenosis. Dyskinesia, seen in 7% of the segments, was equally distributed between both groups with significant stenosis. Sensitivity and positive predictive value in identifying specific coronary vessel disease was similar for both isometric and dynamic exercise. In conclusion, heavy isometric exercise in patients who have had myocardial infarction induces wall motion abnormalities of a severity proportional to the degree of coronary narrowing. This exercise method is similar to dynamic exercise for ability in identifying obstructions in a specific vessel. Furthermore, when compared at near-equal rate-pressure products, heavy isometric exercise is far superior in sensitivity to dynamic exercise.

Adult↗
PubMed1992

Influence of ocular tropicamide on exercise testing.

This study was aimed to evaluate the effects of tropicamide 0.5% eye drops on cardiovascular parameters during exercise testing. The study group included 154 healthy subjects (mean age: 44.7 +/- 8 years). The subjects were divided into three groups according to the size of the pupils at the onset of exercise: A: pupils not dilated (n = 27), B: pupils partially dilated (n = 90) and C: pupils widely dilated (n = 37). They were compared to 66 healthy controls (age 43.8 +/- 8) who did not receive the drops. Rest and exercise parameters were affected in groups A and B, while the results of group C resembled those of the controls: (a) resting heart rate -66.7, 66.6, 70.9 and 69.3, respectively (p = 0.03); (b) heart rate at 50 and 100 W - 104, 107, 110 and 111 (p = 0.01) and 131, 131, 137, 139, respectively (p = 0.01); and (c) peak systolic blood pressure - 192, 186, 183, 175; respectively (p = 0.004). Reanalyzing the data by scoring of visual impairment gave identical results. As a whole, the study group achieved higher work loads than the controls (126 vs. 119 W; p = 0.03). We conclude that the instillation of ocular tropicamide has definite effects on cardiovascular parameters, both at rest and during exercise. Mainly, patients showed a lower heart rate at the initial levels of exercise. However, at symptom-limited level, tropicamide does not influence a patient's ability to achieve the target heart rate, and stress testing results are not altered by the drug.

Adult↗
PubMed1991

Pronounced reduction of aortic flow velocity and acceleration during heavy isometric exercise in coronary artery disease.

Doppler-derived parameters of aortic flow were examined during heavy isometric exercise in 48 men with coronary artery disease (CAD) and in 48 gender- and age-matched healthy controls. The aim was to determine which parameters best separated the groups and to look for a possible relation between exercise-induced Doppler patterns and the extent of CAD. Isometric exercise was performed with a 2-hand bar dynamometer, and the subjects were required to perform 50% of maximal voluntary contraction for 2 minutes. Examination was performed with a pulsed Doppler transducer positioned at the suprasternal notch. Resting peak flow velocity, acceleration time, stroke volume index and cardiac index did not show significant differences between the groups. However, mean acceleration and stroke work were significantly lower in patients with CAD. In this group, exercise peak flow velocity decreased from 98 +/- 13 to 55 +/- 12 cm/s, flow velocity integral from 14 +/- 3 to 7 +/- 3 cm, mean acceleration from 11 +/- 0.9 to 4.7 +/- 1 m/s/s, and stroke volume index from 41 +/- 6 to 23 +/- 4 ml/m2 (p less than 0.001 for all). Cardiac index decreased from 2.7 +/- 0.4 to 2 +/- 0.2 liters/min/m2 (p less than 0.05). Acceleration time increased from 82 +/- 6 to 116 +/- 7 ms. In most of the indexes, the directional changes induced by isometric exercise were similar in patients with CAD and in normal control subjects. The differences compared with the rest values were significantly greater in the CAD group, and especially in patients presenting with 3-vessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

The effects of hormone replacement therapy in normal postmenopausal women: measurements of Doppler-derived parameters of aortic flow.

In this study the effects of hormone replacement therapy on cardiac function in healthy postmenopausal women were evaluated by Doppler echocardiography that was performed before (T1) and 2.5 months after the initiation of hormone replacement therapy (T2) in the peak estrogenic phase. The following parameters of aortic flow were measured: peak flow velocity, acceleration time, and ejection time. Additional parameters were calculated: flow velocity integral and mean acceleration. The study group included 24 postmenopausal women aged 43 to 60 years (mean 51.6 years). The control group consisted of 19 postmenopausal women aged 46 to 60 years (mean 53.5 years) who were not receiving hormone replacement therapy and who underwent the same evaluation. There were no changes in all Doppler parameters between T1 and T2 in the control group. However, in the study group there were significant increases in peak flow velocity (108.3 +/- 16.7 cm/sec at T1 vs 123 +/- 20.7 cm/sec at T2; p = 0.002), flow velocity integral (17.7 +/- 3.9 vs 21.5 +/- 4.7 cm; p = 0.0003), mean acceleration (11.5 +/- 1.9 vs 13.1 +/- 2.6 m/sec/sec; p = 0.001), and ejection time (324 +/- 37.6 vs 348.8 +/- 40.7 msec; p = 0.002). There was no change in acceleration time (94.8 +/- 6.6 vs 95 +/- 10.9 msec). These results demonstrate that estrogens increase both stroke volume and flow acceleration. The latter probably reflects a combination of enhanced inotropism and vasodilatation. We assume that the cardioprotective effect of hormone replacement therapy in postmenopausal women may be due not only to changes in lipid profile but also to direct effects of estrogens on central and peripheral hemodynamic parameters.

Adult↗
PubMed1990

Altered left ventricular volume and ejection fraction responses to supine dynamic exercise in athletes.

Two-dimensional echocardiography was used to determine the responses of left ventricular volumes, ejection fraction and segmental left ventricular motion to supine dynamic exercise in 22 professional athletes, comparing these responses with those in 22 age- and gender-matched healthy untrained individuals. End-systolic volume was significantly greater at rest and during exercise in the athletes (50 +/- 6 versus 29 +/- 4 ml and 40 +/- 5 versus 17 +/- 4 ml, respectively, p less than 0.001 for both). It decreased during exercise in all the untrained subjects, but did not change or increased in nine athletes (41%). End-diastolic volume was greater in the athletes at rest (143 +/- 12 versus 98 +/- 9 ml) and during exercise (157 +/- 14 versus 121 +/- 13 ml, p less than 0.01 for both). It increased in all the untrained subjects, but decreased or did not change in six athletes (27%). Ejection fraction was significantly lower in the athletes at rest and during exercise (65 +/- 4% versus 70 +/- 5% and 73 +/- 5% versus 86 +/- 5%, p less than 0.01 and 0.001, respectively); the values augmented normally in all the untrained subjects, but increased only by less than 5% units, did not change or decreased in nine athletes (41%). Eight athletes (36.5%) failed to demonstrate the expected symmetric hyperkinetic wall motion changes during exercise, which were seen in all the untrained subjects. No correlation was found between atypical responses to exercise and electrocardiographic patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Arm exercise training in the rehabilitation of patients with impaired ventricular function and heart failure.

Although exercise training is an accepted part of comprehensive coronary care programs in patients with coronary artery disease, it still remains to be demonstrated whether or not exercise training should also be applied to patients with impaired ventricular function. Circumstantial evidence exists that patients with impaired ventricular function may eventually benefit from an individually adapted exercise training program provided that contraindications for acceptance of cardiac patients to such a program are well observed. Our study is based on 22 patients with impaired ventricular function, of which 18 were at least 6 months after a Q-wave myocardial infarction and the remaining 4 after coronary artery bypass grafting. Eleven patients with impaired left ventricular function performing upper extremity (arm) ergometry were followed up for 36 months. These patients were trained twice weekly with exercise periods of 30 min duration. The reason for choosing arm ergometry training was that the peak heart rate obtained in arm ergometry is higher when compared to leg ergometry. Rate-pressure product and heart rate were higher for given submaximal work tasks in arm ergometry, while maximal work aerobic capacity was found to be lower in comparison to leg work. The assessment of our patients was based on cardiopulmonary testing, continuous electrocardiographic monitoring (48 h), two-dimensional echocardiography and equilibrium multigated radionuclide ventriculography (99mTc). Group 1, consisting of 11 patients with left ventricular ejection fraction (LVEF) 30.1 +/- 9.5%, were trained by arm exercise for 3 years with a significant increase in work capacity and LVEF. Group 2 consisted of 11 patients with LVEF 25.5 +/- 6.8% who underwent a 12 months' calisthenic program. Peak work capacity and LVEF remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1989

Painful versus silent myocardial ischemia during leg and arm exercise testing in stable angina pectoris.

When 51 patients with proven coronary heart disease and stable angina pectoris underwent exercise testing, 22 experienced painful myocardial ischemia during both leg and arm exercise testing (group L + A), whereas 29 patients had such episodes only during the leg testing (group L). Upright bicycle exercise was performed with the legs first, followed 2 days later by arm testing. Exercise was stopped when typical anginal pain and greater than 1-mm ST horizontal depression occurred during leg testing, and when greater than 1-mm ST horizontal depression was noted during arm testing. Heart rate, systolic blood pressure and rate-pressure product for leg and arm testing, either at the beginning of anginal pain or at the time when 1-mm ST depression was noted, were similar. Two-dimensional echocardiography showed that the L group had higher (p less than 0.01) end-systolic volume at rest and decreased (p less than 0.05) ejection fraction during exercise. Coronary angiography showed that the L group had a greater (p less than 0.001) number of patients with 3-vessel disease, a decreased (p less than 0.001) ejection fraction and less patients with 1-vessel disease. In these patients, absence of anginal pain during arm exercise suggests defective segmental transmission of pain sensation related to severe coronary artery disease. Thus, arm testing, in addition to leg testing, seems to be a simple and useful tool for the detection of severe coronary disease.

Angina Pectoris↗
PubMed1989

Left ventricular exercise echocardiographic abnormalities in apparently healthy men with exertional hypotension.

Of a total of 1,435 healthy untrained asymptomatic individuals referred for a routine periodic checkup, 23 subjects with exertional hypotension on upright bicycle stress testing were identified. All were male. This study assesses by means of echocardiography the responses to exercise of left ventricular (LV) volumes, ejection fraction and segmental LV contractility in these subjects. Exertional hypotension was defined as a decrease in systolic blood pressure to below the resting value at the end of stress test. Supine systolic blood pressure after exercise was significantly greater in the control group than in the study group (179 vs 121 mm Hg, respectively; p less than 0.001); there was no significant intra- or intergroup difference in the resting values. In the study group end-systolic volume was 37 ml at rest and 35 ml after exercise; ejection fraction varied from 65% at rest to 63% after exercise. The sex- and age-matched control group with a normal systolic blood pressure response to exercise showed a shift from 35 to 23 ml and 65 to 77%, respectively (p less than 0.01 and 0.001). Ejection fraction correlated well with radionuclide angiography values. Exertional hypotension was noted after both upright and supine exercise. The pattern of regional wall motion remained unchanged or was hypokinetic in 87% of the subjects; only 13% presented the normally expected hyperkinesia after exercise. This study demonstrates that exertional hypotension is accompanied by an abnormal LV performance.

Adult↗
PubMed1989

Usefulness of immediate postexercise two-dimensional echocardiography in post-myocardial infarction patients without ischemic ECG changes in stress testing: comparison with radionuclide angiography.

Of 38 post-myocardial infarction (MI) applicants for a cardiac rehabilitation program, 17 (45%) did not have ischemic ECG changes in exercise testing. Ten (59%) of these 17 patients had echocardiographic wall motion abnormalities at rest. Immediate postexercise two-dimensional echocardiography demonstrated exercise-induced changes in 8 (47%) patients (2 with normal and 6 with abnormal results from rest studies). The comparative radionuclide (RNA) examinations showed that there were 6 patients with abnormal findings from rest RNA; exercise-induced changes were detected in 7 (44%) of 16 patients (3 with normal and 4 with abnormal results from rest RNA tests). Statistical analyses, using RNA as reference point, revealed that the total correctly diagnosed cases for the echocardiographic rest studies was 13/17 (77%) and for the exercise studies, 13/16 (81%). The negative predictive values were 7/7 (100%) and 7/8 (88%), respectively. The corresponding positive predictive values were 6/10 (60%) and 6/8 (75%). The same pattern was observed when each segment (septal, apical, and posterolateral) was evaluated separately. The authors conclude that in post-MI patients with a negative stress test, the efficacy of postexercise echocardiography equals that of RNA in the identification of additional patients with ischemia.

Adult↗
PubMed1988

Echocardiographic evaluation of the effects of gallopamil on left ventricular function.

Two-dimensional echocardiography was used to determine global and regional left ventricular function in 32 patients treated with gallopamil (methoxyverapamil) for angina pectoris. Ejection fraction (EF), pressure/volume ratio (PVR), and segmental wall motion were assessed. Evaluations were made before therapy (T1) and repeated 3 weeks later; this assessment included examination 2 and 8 hours after the morning dose (T2 and T3, respectively). Patients were randomized to either a placebo group or three study groups (25, 37.5, and 50 mg t.i.d.). In the 37.5 and 50 mg groups there was an increase in EF (T1 = 53.8% and 54.5%, T2 = 57.9% and 60.1%, and T3 = 57.6% and 60%) and PVR values (T1 = 5.2 and 7.2 mm Hg/ml/m2, T2 = 5.8 and 7.7 mm Hg/ml/m2, and T3 = 5.9 and 7.6 mm Hg/ml/m2, respectively). Wall motion remained the same or improved in 92.3% of the patients. In conclusion, gallopamil had no cardiodepressant effects in most patients. On the contrary, EF, PVR, and segmental contractility tended to improve with the higher doses.

Aged↗
PubMed1988

Contraindications to physical training in patients with impaired ventricular function.

Exercise performance in patients with impaired ventricular function does not correlate well with the severity of dysfunction. Patients with ventricular dysfunction can achieve a fairly high work capacity, and the physiological variables respond in a similar way, regardless of whether or not the patients do or do not have impaired function. Furthermore, patients with pump dysfunction can benefit from a supervised physical training programme by improving their functional capacity and thus, their quality of life. The absolute contraindications for exercise therapy in this group of patients with coronary artery disease should therefore be identical to those who have normal ventricular function. In our opinion, special attention should be exercised in patients who have chronotropic incompetence, lack of an elevation or decrease in blood pressure during exercise performance and in those whose stroke volume is not elevated during even low to moderate work-loads. Recommendations as to the implication of exercise therapy as a therapeutic modality in patients with ventricular impairment must be accepted with caution. The reason for this is that our observations are based on historical, anecdotal trials, most of which included only a modest number of patients. Future research and a prolonged follow-up is needed in order to obtain both a more exact analysis and eventually scientifically based evidence on the benefits and hazards involved.

Coronary Disease↗