Systolic Time Intervals In Patients Research Articles

Evaluation of Systolic Time Intervals in Patients of Ischemic Heart Disease with Clinical Heart Failure

Introduction: Left ventricular (LV) systolic function evaluation is based on ejection fraction assessment. Due to the great sensitivity of the examination and the ease of measurement, systolic time intervals (STIs) are ideally appropriate for studying the effects of pharmacologic agents upon the heart. In this context, the present study aimed to estimate and compare STI in patients with ischemic heart disease (IHD) with clinical heart failure and among control subjects without clinically established LV dysfunction based on their LV ejection fraction (LVEF). Materials and Methods: This case–control study included 33 IHD patients as cases and 32 healthy subjects as controls. All subjects underwent pulsed-Doppler echocardiogram to estimate STIs: total electromechanical systole (QS2), preejection period (PEP), and LV ejection time (LVET). Results: A significant difference between PEP (145.23 ± 23.20 vs. 82.99 ± 8.63, P < 0.00001), LVET (231.34 ± 40.89 vs. 265.39 ± 31.98, P = 0.000947), and PEP/LVET ratio (0.63 ± 0.15 vs. 0.31 ± 0.08, P < 0.00001) between cases and controls was found. On subgroup analysis, a weak correlation was found in patients with LVEF ≤40% and PEP/LVET (r = −0.3677, P = 0.1958). In addition, a relatively strong correlation between LVET and heart rate (r = −0.432, P = 0.012) was found among the cases. Conclusion: The current study results showed that the differences in the values of STI among cases than in controls could be an indicator of LV systolic dysfunction. In addition, this method may have impending applications in the management of IHD.

Effects of Dobutamine and Levosimendan on Systolic Time Intervals in Patients with Decompensated Heart Failure

Background/Objective: Levosimendan represents an alternative to other positive inotropic agents based on its different mechanisms of action and favorable electrophysiological properties. This study compared the effects of levosimendan and dobutamine on echocardiographic parameters in heart failure patients with acute decompensation necessitating positive inotropic support. Methods: Patients with acute decompensated heart failure were randomized to receive inotropic support with either levosimendan (n=25) or dobutamine (n=25). Treatment groups were compared in terms of echocardiography measurements including tissue Doppler examination findings, systolic time interval assessments and diastolic parameters. In addition, groups were compared for demographic features, clinical characteristics and laboratory findings. Results: Among tissue Doppler measurements, Sm-lateral and Sm-septal significantly increased after treatment in both groups. E/E’ lateral and E/E’ septal significantly decreased only in the levosimendan group. Among systolic time interval parameters, increasing in left ventricular ejection time and shortening in pre-ejection period are similar in both groups, however a significant decrease in QS2i was observed in the levosimendan group. Levosimendan treatment was associated with significant decreases in blood pressures along with a significant increase in ejection fraction. Dobutamine treatment on the other hand resulted in significant increases in blood pressure, heart rate and ejection fraction. Conclusions: Our findings suggest that levosimendan and dopamine treatments are associated with only marginal differences in echocardiographic parameters. This study suggests that both levosimendan and dobutamine are almost equally effective in systolic time intervals. However, levosimendan appears to have additional advantage over dobutamine in shortening QS2i, indicating a fairly strong positive inotropic effect. Keywords : decompensated heart failure, dobutamine, levosimendan, inotropic support, echocardiography, tissue doppler, systolic time intervals DOI : 10.7176/JSTR/5-3-07

Duchenne型進行性筋ジストロフィー症の左室収縮時間による経年的左心機能評価3年間のfollow up study

Duchenne型進行性筋ジストロフィー症の左室収縮時間による経年的左心機能評価3年間のfollow up study

Effects of Levosimendan and Dobutamine on Systolic Time Intervals in Patients with Acute Decompensated Heart Failure

Effects of Levosimendan and Dobutamine on Systolic Time Intervals in Patients with Acute Decompensated Heart Failure

Characteristics of systolic time intervals in patients with pheochromocytoma.

The effect of chronic catecholamine excess on cardiac function was assessed in 8 patients with surgically proven pheochromocytoma and the results compared with data obtained from normal controls and essential hypertensives. Major findings in systolic time intervals (STI) in patients with pheochromocytoma were a marked shortening of electromechanical systole and left ventricular ejection time (ET), but pre-ejection period (PEP) remained within normal limits. These findings were not altered by correction for heart rate. The ET/PEP ratio was very low (1.87 +/- 0.31) due to the remarkable shortening of ET. The ET/PEP ratio in essential hypertensives was also low (1.77 +/- 0.38), but this was mainly due to a remarkable prolongation of PEP. Low cardiac index, low stroke index and high total peripheral resistance index were preoperative characteristics in patients with pheochromocytoma, but returned to normal after operation. These results suggest that chronic excessive production of catecholamines from pheochromocytoma has deleterious effects on the heart, and that wide differences in STI exist between patients with pheochromocytoma and those with essential hypertension.

Clinical significance of systolic time intervals in hypertensive patients

This paper updates the current view on clinical significance of systolic time intervals (STI) in estimating the cardiac changes associated with hypertension. The following three intervals were measured as STI: (1) electromechanical systole (QS2 interval); (2) left ventricular ejection time (LVET) and (3) pre-ejection period (PEP). Firstly, the influences of changes in heart rate, preload, afterload and myocardial contractility upon each interval were reviewed; secondly, clinical applications of STI in various types of hypertension such as essential hypertension, hypertension with angina pectoris and pheochromocytoma were studied. In patients with essential hypertension, there was a good positive correlation between PEP and left ventricular mass, and a shortening of LVET was observed only at the decompensated stage. The changes in STI in angina pectoris with or without hypertension were similar and were different from those in essential hypertensives. STI in patients with pheochromocytoma were characterized by a marked shortening of QS2 and LVET with normal PEP. These findings indicate the usefulness of STI in detecting cardiac changes in various types of hypertension.

Effect of prolonged intense endurance training on systolic time intervals in patients with coronary artery disease

We studied the effect of exercise training (ET) on systolic time intervals (STI) in 13 patients with coronary artery disease (CAD). All patients trained for at least 10 months. They exercised three times/week at 50% to 70% of maximal oxygen uptake (V̇O 2max) for the initial 3 months and at least four times/week for approximately 50 minutes at 70% to 90% of V̇O 2max thereafter. A significant training effect was documented by an increase in V̇O 2max from 26.0 ± 4.3 to 37.2 ± 5.8 ml/kg/min ( p < 0.01), a lower heart rate (HR) at rest, and a lower blood pressure and HR during submaximal work. The indices of total electromechanical systole (QS 2I) and left ventricular ejection time (LVETI) did not change. However, pre-ejection period index (PEPI) decreased from 137 ± 9 msec to 129 ± 9 msec ( p < 0.01). PEP LVET decreased from 0.373 ± 0.028 to 0.342 ± 0.032 ( p < 0.01). Left ventricular end-diastolic dimension and posterior wall thickness, measured echocardiographically, were increased after training. We conclude that exercise training may improve myocardial performance in some patients with CAD.

Systolic time intervals: Assessment by isolated cardiac muscle studies

To document the independent effects of acute changes in preload, afterload and inotropic state on the systolic time intervals, 10 isolated rat left ventricular muscle preparations were studied. Experiments were performed using physiologically sequenced contractions that simulate the loading conditions of the intact left ventricle. The preshortening period was measured from the time of the electrical stimulus to the onset of muscle shortening, and the isotonic contraction time was measured as the duration of shortening. These variables are analogous to the preejection period and the left ventricular ejection time in the intact heart. It was found that an isolated increase in preload shortened the preshortening period and prolonged the isotonic contraction time, whereas an increase in afterload prolonged the former and shortened the latter. Isoproterenol shortened both the preshortening period and the isotonic contraction time, while an increase in calcium shortened the preshortening period and lengthened the isotonic contraction time. All changes were significant (p less than 0.01) by analysis of variance. Thus, the similar dependence of preshortening period, isotonic contraction time and clinical systolic time intervals on changes in preload, afterload and inotropic state supports the derivation of systolic time intervals from fundamental principles of myocardial mechanics. These data provide an improved basis for the rational interpretation of systolic time intervals in patients with and without heart disease.

Evaluation of systolic time intervals in patients with angina pectoris

We have explored the systolic time intervals of 52 patients with angina pectoris at the time of their hospitalization in our wards. Our results are in close agreement with published data, essentially indicating prolongation of the preejection time and shortening of the ejection time. These alterations of systolic times can be interpreted pathophysiologically as expressing reduced myocardial contractility. The long PEP-short LVET polygraph picture, occurring in the course of chronic ischemic heart disease, reveals the deficit of myocardial contractility at a stage of the disease at which clinical evidence of left ventricular failure is usually not yet detectable.

Pindolol and systolic time intervals in patients with hypertension

Two studies of systolic time intervals (STIs) in patients with mild to moderate hypertension (HBP) revealed that no mean change in systolic intervals occurred with pindolol therapy, although some patients had significant alterations in their STIs. Pindolol responders with normal pretreatment preejection period to left ventricular ejection time ( PEP LVET ) ratios had a significant increase in this ratio following pindolol therapy, whereas those with abnormal pretreatment PEP LVET ratios had improvement in this ratio on administration of the drug. Patients on propranolol showed no change in PEP LVET ratio. Propranolol administration slowed heart rate and lengthened Q-S2, S1-S2, and LVET, however, without altering the Q-S2 and LVET index, indicating that the changes were caused by the effect of propranolol on the heart rate alone. Chlorthalidone in high doses significantly reduced the Q-S2 index and the S1-S2 index, indicating that these changes were not caused by alteration of the heart rate. The second study suggests that STIs may provide a predictive clue for clinical response to pindolol. Patients with normal cardiac function (group I) are more likely to respond to pindolol than are those with abnormal cardiac function (group II). Directionally opposite changes in STIs in the two subgroups suggest different mechanisms for changing cardiac function. Pindolol's dual role as a beta-blocking agent with intrinsic sympathomimetic activity is proposed as a possible explanation, beta-blocking effects predominating in group I and sympathomimetic activity balancing the beta effect in group II.

Relation of kinetocardiogram to systolic time intervals in patients with old myocardial infarction.

Left ventricular function was studied noninvasively in a group of 35 patients with noncomplicated and complicated old myocardial infarction (MI) by means of kinetocardiography (KCG) and systolic time intervals (STI). Discriminant analysis with a group of 130 normal subjects documented that STI were significantly abnormal and that the abnormalities, i.e. prolongation of the preejection period, shortening of left ventricular ejection time and increase of PEP/LVET were more evident in patients with complicated old MI. KCG was more or less abnormal in all the patients studied, with the more striking abnormalities in those with complications. A good correlation was found between KCG and STI abnormalities. We consider that KCG is able to detect in a sensitive way abnormalities of left ventricular contraction in patients with old MI and that, most probably, alterations of STI in these patients are mainly due to incoordinate left ventricular contraction.

Left ventricular systolic time intervals in patients with acute myocardial infarction.

Left ventricular systolic time intervals were measured daily during 601 episodes of acute myocardial infarction. The ratio of pre-ejection period to ejection period during the first 24 hours permitted patients to be arranged in six prognostic groups with mortalities while in hospital ranging from 4 to 60 per cent. The only factors completely independent of the systolic time intervals which were shown statistically to be associated with high mortality while in hospital were defects in atrioventricular and intraventricular conduction.

Improved right ventricular systolic time intervals after digitalis in patients with cor pulmonale and chronic obstructive pulmonary disease

Although digitalis has been used to treat patients with cor pulmonale secondary to chronic obstructive pulmonary disease, its effect on right ventricular performance has not been conclusively determined. This study assessed the effects of acute digitalization on measurement of right ventricular systolic time intervals in patients with chronic obstructive pulmonary disease and cor pulmonale. The intervals were recorded before and 40 minutes after administration of ouabain, 1 mg intravenously, in nine men (mean age 58 ± 5 [standard deviation] years) with chronic obstructive pulmonary disease (mean maximal mid expiratory flow rate 0.29 ± 0.08 1 liters/sec) and electrocardiographic evidence of right ventricular hypertrophy. Ouabain produced significant reductions in right ventricular systolic time intervals, including the right ventricular preelection period (from 117 ± 23 to 102 ± 16 msec; P < 0.01), right ventricular ejection time index (from 397 ± 33 to 375 ± 24 msec; P < 0.01) and mean Q-P 2 index (from 509 ± 23 to 474 ± 8 msec; P < 0.001). In eight patients with simultaneously measured left ventricular systolic time intervals, similar changes were observed, including shortening of the left ventricular preejection period index (from 135 ± 9 to 117 ± 11 msec; P < 0.01), ejection time index (from 395 ± 18 to 379 ± 20 msec; P < 0.01), and the mean Q-A 2 interval (from 530 ± 16 to 495 ± 16 msec; P < 0.001). There were no significant changes in aortic or pulmonary arterial pressures. The results demonstrate that acute administration of digitalis produces significant improvement in right ventricular performance in patients with chronic obstructive pulmonary disease and cor pulmonale. The simultaneous shortening of right and left ventricular systolic time intervals is of comparable magnitude.

Effect of Isometric Handgrip On Systolic Time Intervals in Patients With Ischemic Heart Disease and Cyclic Amp Phosphodiesterase Inhibitor Pretreatment

The effect of cAMP phosphodiesterase inhibitor EG626 on the left ventricular function was studied in 23 patients with ischemic heart disease at rest and during the IHG test. Administration of a single dose of the substance produced changes in STIs indicating an increase in cardiac output and a possible enhancement of myocardial contractility during the IHG test. EG626 may have a beneficial effect on impaired left ventricular function in patients with ischemic heart disease.

Effects of sustained isometric handgrip on ventricular systolic time intervals in patients with ischemic heart disease. Inotropic state of the left ventricle during treatment with perhexiline maleate and with propranolol.

It was found from our previous studies that patients suffering from ischemic heart disease with angina, showed either one of the patterns of the left ventricular systolic time intervals on isometric handgrip exercise.Patients in class I or II NYHA showed a shortened pre-ejection period corrected for heart rate (PEPI), and a prolonged ejection period corrected for heart rate (LVETI) together with a decrease of the PEP/ LVET ratio. This response is normal, because it has also been found in normal subjects.The patients in class III or IV NYHA showed a prolongation of PEPI, shortening of LVETI and an increase of the PEP/LVET ratio. This response is abnormal, because it occurs in patients with impaired cardiac performance and in ischemic ones with widespread asynergic areas.Our aim here is to study the response of these 2 groups of patients treated for a 4-week period with perhexiline maleate. This new drug is chiefly used as anti-anginal drug, though it also has anti-arrhythmic properties.The results show that the response of the left ventricle to isometric handgrip exercise in class I or II patients following perhexiline maleate treatment, is almost normal, thus confirming that the drug has no side effects on the cardiodynamics checked by the left ventricular systolic time intervals.The responses of class III or IV patients after perhexiline maleate become normal. This shows that the drug acts by removing the contractile dysfunction. It can reasonably be assumed that this takes place following the elimination of the ischemia induced dyssynergic areas.The effect of this drug has also been evaluated from a clinical point of view. A marked decrease in the frequency of anginal crises and the consequential reduction in the consumption of trinitroglycerin pills during perhexiline maleate treatment could thus be observed.

Evaluation of Left Ventricular Performance in Acutely III Patients with Chronic Obstructive Lung Disease

Among 28 patients with chronic obstructive pulmonary disease (COPD) with increasing dyspnea, the resting mean pulmonary arterial wedge pressure was elevated (greater than 12mm Hg) in 4 and became abnormal with exercise in 3 other subjects. Stroke volume index was reduced (less than 36 ml/beat/M2) in 16 of 26 patients (62 percent). The resting pre-ejection period index was prolonged (greater than 144 msec) in 17 patients (65 percent), while the left ventricular (LV) ejection time index was reduced (less than 408 msec) in 23 patients (88 percent). The ratio of the pre-ejection period to the LV ejection time was within the normal range (0.309 to 0.381) in only 3 of 26 patients (12 percent). Echocardiographic measurements of LV function were normal in nine patients, seven of whom had one or more abnormal values for systolic time intervals (STIs). These data suggest that reduced LV filing results in abnormal values for STIs in patients with COPD, and therefore that in such patients STIs are not accurate indices of LV function.

Systolic time intervals during submaximal and maximal exercise in man

This study describes the serial responses of the systolic time intervals (STI) to submaximal and maximal supine exercise in normal subjects. Regression equations relating STI and heart rate during supine submaximal and maximal exercise are derived. It is shown that within the heart rate range of 120 to 170 beats per minute, total electromechanical systole (QS 2) and left ventricular ejection time (LVET) are related inversely and linearly to heart rate for both levels of exercise. At comparable heart rates, the QS 2 and LVET are greater during maximal than submaximal exercise, with differences widening significantly with increasing heart rate. This finding points out the importance of taking into account the intensity of exercise when evaluating STI responses to exercise stress in different groups. The pre-ejection period (PEP) significantly decreases from rest to the initial phase of both maximal and submaximal exercise with a subsequent tendency to plateau, indicating that a minimum PEP is reached early during exercise and that cardiovascular adaptation no longer includes additional shortening. This study also shows that STI obtained during exercise cannot be corrected for heart rate according to regression equations which were developed in resting supine subjects. Thus, there appears to be no justification for extrapolating the heart rate range of resting supine subjects to the exercise state for correcting intervals in this manner. In addition, STI measurements made during the immediate recovery period following supine exercise are significantly different from those obtained just prior to cessation of exercise. Therefore, recovery STI do not reflect the true hemodynamic changes occurring during the course of exercise. The application of the levels of exercise described in this study to the assessment of changes in STI in patients with documented or suspected cardiac dysfunction appears warranted. Alterations in left ventricular performance not evident at rest or following mild exercise might be detected employing these more strenuous exercise protocols. Using the regression equations established in this study, exercise-induced deviation in STI corrected for heart rate may now be determined with the realization that these relationships were derived from relatively young men. However, in the adult population the duration of LVET corrected for heart rate varies little with advancing age, and PEP shows only a slight increase. 34,35

Systolic Time Intervals

The diagnosis of tight aortic stenosis is always an important consideration in patients with congestive heart failure of unknown origin. Inasmuch as the typical systolic murmur of aortic stenosis may be soft and difficult to hear under such circumstances, this diagnosis may be missed or, at best, difficult to confirm. We examined phonocardiograms with carotid pulse recordings and measured systolic time intervals in patients with aortic stenosis and congestive heart failure to determine if systolic time intervals were of any help. Left ventricular ejection time (LVET) was prolonged in seven of nine patients. The pre-ejection period (PEP)/LVET ratio in all nine cases was found to be much lower than values reported for congestive heart failure from other causes. It is believed that the PEP/LVET ratio is very helpful in distinguishing congestive heart failure due to aortic stenosis from congestive heart failure caused by other diseases and may be very helpful

Systolic time intervals. Use in congestive heart failure due to aortic stenosis.

The diagnosis of tight aortic stenosis is always an important consideration in patients with congestive heart failure of unknown origin. Inasmuch as the typical systolic murmur of aortic stenosis may be soft and difficult to hear under such circumstances, this diagnosis may be missed or, at best, difficult to confirm. We examined phonocardiograms with carotid pulse recordings and measured systolic time intervals in patients with aortic stenosis and congestive heart failure to determine if systolic time intervals were of any help. Left ventricular ejection time (LVET) was prolonged in seven of nine patients. The pre-ejection period (PEP)/LVET ratio in all nine cases was found to be much lower than values reported for congestive heart failure from other causes. It is believed that the PEP/LVET ratio is very helpful in distinguishing congestive heart failure due to aortic stenosis from congestive heart failure caused by other diseases and may be very helpful

Systolic time intervals in patients with artificial pacemakers: Noninvasive technique for assessing atrial contribution to stroke volume at various P-R intervals

Systolic time intervals were measured in 11 patients with a transvenous ventricular demand pacemaker. There was a close relation between atrioventricular conduction time (P-R interval) and both left ventricular ejection time and preejection period; a P-R interval of 180 to 200 msec was associated with a maximal left ventricular ejection time, a minimal preejection period and an optimal stroke volume. Thus, by employing the noninvasive technique of measuring systolic time intervals, we were able to confirm that a properly timed atrial contraction makes an important contribution to the enhancement of stroke volume of the left ventricle.