A Cantor

Soroka Medical Center, Be'er Sheva`, Southern District, Israel

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Publications (19)56.09 Total impact

  • N Cristal, A Cantor
    Journal of Electrocardiology 05/1995; 28(2):165-7. · 1.09 Impact Factor
  • A Cantor, N Cristal
    Harefuah 06/1993; 124(9):592, 596.
  • A Cantor, N Hendler, N Cristal
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    ABSTRACT: A case report of a patient with persistent left anterior hemiblock admitted with acute ischemic heart disease is described. At effort during follow-up evaluation, the patient complained of retrosternal pain when the heart rate was 124 beats/min. No pathological ST-T changes were demonstrated at this time. At 133 beats/min, the precordial pain increased, the QRS axis displayed a marked shift to the right, and ischemic ST-T depression was recorded. In discussing this unreported phenomenon, it is pointed out that left anterior hemiblock does not necessarily represent an anatomical block of the atrioventricular bundle but may simply reflect a relative delay in conduction. In addition, acute ischemia may change the physiological behavior of the system resulting in slower conduction through the posterior rather than through the anterior atrioventricular bundle. The influence of left anterior and left posterior hemiblock on ischemic ST-T changes and on the coronary flow distribution is discussed.
    Journal of Electrocardiology 08/1992; 25(3):237-41. · 1.09 Impact Factor
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    ABSTRACT: The hypothesis that endogenous opioids may be involved in reduced exercise-induced ischemic pain or in silent ischemia was tested. Fifteen male patients with coronary artery disease were tested in a randomized, double-blind crossover study. After a preliminary screening effort test they were divided into two groups: the first group of nine patients received an i.m. injection of naloxone 0.4 mg, or saline as placebo, and the second group, comprising six patients, received 4 mg naloxone or saline i.v. Effort testing was performed at weekly intervals on an ergometric bicycle, following the Bruce protocol. ECG, heart rate, blood pressure and pain perception were monitored continually. Blood was sampled through an indwelling venous catheter for beta-endorphin determination before, at the peak of, and 10-20 min following exercise. ST depression, heart rate, blood pressure and the double product were similar after naloxone and following saline administration. Beta-endorphin concentrations in plasma were significantly increased following exercise in the second group of patients. The increase in beta-endorphin concentration was larger when the patients were pretreated with naloxone (4 mg) than with placebo. However, chest pain was not significantly altered by either dose of naloxone.
    Israel journal of medical sciences 03/1990; 26(2):67-71.
  • A Cantor, N Cristal
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    ABSTRACT: The objectives of this study were (a) to evaluate the dose-response effect of isradipine, a dihydropyridine calcium antagonist, on the heart rate and blood pressure of males with mild to moderate hypertension; and (b) to compare these results with those obtained with propranolol, a beta-adrenoceptor blocker, on a matched patient population. Twenty-four patients entered a single-blind study, beginning with a 2-week washout placebo period followed by a forced-titration period. Treadmill and hand-grip tests were also performed. Two weeks were allocated to each stage of the therapy. The end point of the study was normalization of blood pressure with a minimum of side effects. Results and conclusions include the following: both drugs were effective in reducing systolic blood pressure (SBP) and diastolic blood pressure (DBP), but isradipine was more effective in reducing the DBP; isometric exercise can predict accurately the results of the isotonic exercise; the maximum therapeutic effect of propranolol was achieved during the second study-dose level; increases in the isradipine dose were reflected in a proportional reduction of SBP and DBP; and the incidence of side effects is lower among isradipine-treated patients compared to propranolol-treated patients.
    Journal of Cardiovascular Pharmacology 02/1990; 15 Suppl 1:S76-8. · 2.38 Impact Factor
  • A Cantor, B Gold
    Israel journal of medical sciences 03/1988; 24(2):128-9.
  • N. Cristal, A. Cantor, Y. Hochberg
    Current Opinion in Cardiology 01/1988; 3. · 2.56 Impact Factor
  • A Cantor, M Gueron
    Harefuah 08/1987; 113(1-2):42-4.
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    ABSTRACT: We compared the effect of two exercise stress tests on blood pressure in normal and borderline populations. The aim of the trial was to determine if isometric exercise testing by handgrip can replace the isotonic exercise test in population screening for the detection of mild and latent hypertension. The study involved 150 subjects; 62 were normotensive and 88 were borderline hypertensive. No significant statistical difference was found in diastolic pressure between the tests. In normotensive subjects, the diastolic response after isotonic effort was 79.3 +/- 9.6 mm Hg and 89.0 +/- 9.7 mm Hg after the isometric test (p less than 0.05). However, both results did not pass 100 mm Hg. In borderline hypertensive patients the diastolic response to the isotonic test was 105.6 +/- 8.8 mm Hg and after the isometric test 107.7 +/- 10.6 mm Hg (NS). The results show that the handgrip isometric test can replace the complicated isotonic test for the screening detection and evaluation of hypertensives in the population.
    Cardiology 02/1987; 74(2):141-6. · 1.52 Impact Factor
  • B Gold, A Cantor, Y Shapiro
    Harefuah 12/1986; 111(9):248-51.
  • A Cantor, D Buskila, M Gueron
    Harefuah 03/1986; 110(3):119-21.
  • Harefuah 01/1986; 109(11):324-7.
  • Harefuah 02/1983; 104(1):11-2.
  • Harefuah 04/1982; 102(6):232-4.
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    ABSTRACT: A significant error may be introduced in intervals measured from the onset of the QRS if an electrocardiographic lead that does not record the earliest deflection is used. To ascertain to what extent the commonly used leads can be relied on to show the earliest QRS onset, 100 normal subjects and 219 patients with heart disease were studied by means of simultaneous recording of three leads: a right precordial lead chosen to show an rS configuration, lead II, and another limb lead chosen to show a qR configuration. Lead II most frequently showed a delayed QRS onset--in 34% of normal subjects and 36% of the patients. In the other limb lead the initial QRS deflection was delayed in 24% of the normal subjects and 23% of the patients. The QRS onset in the right precordial lead was never delayed in the normal subjects; however, it was delayed in this lead in 6% of the patients. The delays in each of the leads ranged from 5-20 msec. We conclude that while a right precordial lead is by far the most reliable single lead that can be used for interval measurements, simultaneous recording of a right precordial lead and a limb lead assures that recording of the earliest QRS onset in all cases.
    Circulation 05/1981; 63(4):933-7. · 15.20 Impact Factor
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    ABSTRACT: Systolic time intervals were measured in 147 healthy 13-19-year-old adolescents to derive regression equations for clinical use in this age group and to determine to what extent they differ from those of children and adults. Stepwise regression analysis showed that heart rate was the only variable consistently and significantly related to electromechanical systole (QS2), left ventricular ejection time (LVET) and preejection period (PEP). None of the other variables tested (age, height, weight, body surface area, blood pressure, hemoglobin, hematocrit and serum electrolytes), when used alone, were relevant variables in relation to QS2, LVET or PEP. The PEP/LVET ratio in adolescents was essentially independent of heart rate, as in children and adults. The regression lines for QS2, LVET and PEP in adolescents fall between those for children and adults, indicating that there is a distinct tendency toward lengthening of all the systolic time intervals with age, independent of changes in heart rate. The PEP lengthens proportionately more than the LVET, resulting in a progressive increase in the mean PEP/LVET ratio from childhood (0.30) to adolescence (0.32) and to adulthood (0.345). The precise hemodynamic factors underlying these changes with increasing age remain to be determined.
    Circulation 02/1981; 63(1):204-9. · 15.20 Impact Factor
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    ABSTRACT: Systolic time intervals were measured in 253 normal children, with careful attention to precise recording and measuring techniques, to derive regression equations which could be used as reliable standards for clinical assessment of left ventricular performance in this age group. Using stepwise regression analysis, a highly significant correlation was found for electromechanical systole (QS2) and for left ventricular ejection time (LVET) with heart rate alone in both males and females, and age was not found to be a relevant variable. Similarly, for the preejection period (PEP) in males, heart rate was the only relevant variable. PEP in females showed a small but significant influence of age in addition to heart rate; in practice, this small influence can be neglected. Regression equations relating each of the systolic time intervals to heart rate alone were therefore derived for clinical use. The PEP/LVET ratio was found to be only weakly correlated with heart rate in males and with age in females, and in practice can be considered to be independent of these variables. The mean value of the PEP/LVET ratio and its standard deviation (0.30 +/- 0.04) can therefore be used for all children. We found that satisfactory recording of systolic time intervals can be obtained with little difficulty in almost all children using the techniques described. The method is therefore practical for clinical use in children, as it is in adults, and the normal standards derived in this study can serve as a reliable basis for its application.
    Circulation 01/1979; 58(6):1123-9. · 15.20 Impact Factor
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    ABSTRACT: Although the precise mechanism of the cardiovascular effects in man evoked by the venom of the yellow scorpion has yet to be completely elucidated, previous studies indicate that excessive adrenergic activity is present in many of the cases. This report describes two patients in whom yellow scorpion sting was followed by bradyarrhythmia with varying degrees of atrioventricular block which promptly regressed after the administration of atropine; this is consistent with a direct parasympathomimetic effect of the venom or with a central effect producing increased vagal tone. It is suggested that the cardiovascular actions of the venom may represent a wide spectrum of effects on the autonomic nervous system, ranging from the predominantly sympathomimetic to the predominantly parasympathomimetic.
    Israel journal of medical sciences 10/1977; 13(9):908-11.
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    ABSTRACT: Continuing improvements in cardiac surgery and a wider selection of young patients for prosthetic valve replacement mean that an increasing number of women of childbearing age will undergo such procedures and will also subsequently become pregnant. At present, most patients with prosthetic heart valves are treated with anticoagulant drugs for life. The main problem with anticoagulant therapy during pregnancy is fetal and maternal hemorrhage. Congenital anomalies have been described in infants born to mothers treated with coumarin derivatives during the first trimester of pregnancy. Dipyridamole is known to decrease the adhesiveness of platelets or their ability to aggregate. We report the successful outcome of four pregnancies in patients with Starr-Edwards prostheses who were treated with dipyridamole during their pregnancies.
    International Journal of Gynecology & Obstetrics 18(2):128-32. · 1.84 Impact Factor