Journal of the Practice of Cardiovascular Sciences

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 6  |  Issue : 1  |  Page : 23--32

Correlation of systolic and diastolic time intervals with demographic and anthropometric parameters in young adults


Sadiqua Sadaf, Mehnaaz Sameera Arifuddin, Mohammed Ziya ur Rahman, Mohammed Abdul Hannan Hazari, Syeda Bushra Quadri 
 Department of Physiology, Deccan College of Medical Sciences, Hyderabad, Telangana, India

Correspondence Address:
Mehnaaz Sameera Arifuddin
Department of Physiology, Deccan College of Medical Sciences, Kanchanbagh (PO), Hyderabad - 500 058, Telangana
India

Abstract

Context: Dimensions of vasculature may vary with height, weight, and build of the individual. This may, in turn, influence the time intervals during cardiac cycle. Aims: The aim of this study was to correlate the systolic and diastolic time (DT) intervals (preejection period [PEP], ejection time [ET], upstroke time [UT], DT, pulse duration [PD], and ejection slope [ES]) of pulse waves recorded from all four limbs in relation to age, gender, weight, height, heart rate, and blood pressure and to compare these cardiac time intervals between individuals with or without parental history of hypertension. Settings and Design: Ninety-eight healthy MBBS students in the age group of 19–21 years were included. Subjects and Methods: Students' history and demographic data were noted. Anthropometric measurements were recorded. The measurement of peripheral arterial pressures (in all four limbs) and determination of cardiac intervals (PEP, ET, UT, DT, PD, and ES) was done by PeriScope. Statistical Analysis Used: Data were analyzed using SPSS version 17.0. Results: Independent sample t-test showed statistically significant differences between genders with weight, height, waist circumference, and waist–hip ratio. Statistically significant differences existed between right arm systolic blood pressure, left arm systolic blood pressure, and left arm pulse pressure among males and females. Significant differences among males and females were observed in some of the cardiac time intervals. Mean arterial blood pressure recorded in all four limbs showed a significant negative correlation with right arm ES in males and left arm ES in females. Conclusion: Since gender, anthropometric parameters, and blood pressure influence cardiac time intervals, these should be adjusted for when deriving inference on left ventricular performance.



How to cite this article:
Sadaf S, Arifuddin MS, Rahman MZ, Hazari MA, Quadri SB. Correlation of systolic and diastolic time intervals with demographic and anthropometric parameters in young adults.J Pract Cardiovasc Sci 2020;6:23-32


How to cite this URL:
Sadaf S, Arifuddin MS, Rahman MZ, Hazari MA, Quadri SB. Correlation of systolic and diastolic time intervals with demographic and anthropometric parameters in young adults. J Pract Cardiovasc Sci [serial online] 2020 [cited 2020 Sep 30 ];6:23-32
Available from: http://www.j-pcs.org/text.asp?2020/6/1/23/282807


Full Text



 Introduction



Cardiac time interval analysis offers an easy, noninvasive, quantitative measure of left ventricular performance in humans because they are sensitive to changes in the autonomic modulation, inotropic state, preload, and afterload. These intervals may be very sensitive indices for detecting heart changes in moderate-to-severe hypertension. Researchers have shown that they can be affected by atherosclerosis, even when cardiac output (CO) and left ventricular chamber dimension remain unchanged.[1]

The important time intervals which are measured are electromechanical systole (QS2), preejection period (PEP), upstroke time (UT), left ventricular ejection time (LVET), diastolic time (DT), and pulse duration (PD). These intervals have been measured noninvasively using echocardiography, sphygmography, carotid pulse recording, or phonocardiography. In earlier times, PEP was measured to evaluate the cardiac systolic function and LVET for analysis of left ventricular stroke volume.[2]

The assessment of heart function as an index of potential myocardial involvement in diabetic patients without clinical evidence of myocardial ischemia or other cardiovascular abnormalities has become increasingly important, and hence, systolic and DT intervals may provide a reasonable correlation in the absence of such obvious clinical or diagnostic abnormality. Rynkiewicz et al. showed that heart rate, diastolic pressure, and PEP/LVET ratio significantly increased and LVET decreased in the diabetic group,[3] whereas Posner et al. did not find any statistically significant difference in diabetics compared to normal individuals.[4] In myocardial diseases, the prolongation of PEP and shortening of LVET is usually present.

Although previous studies have shown the influence of hemodynamic and electrical variables on cardiac time intervals, very few have studied the effect of anthropometric and demographic parameters on these time intervals. This is the reason why this study was conducted.

The aim and objectives of our study were to assess the systolic and DT intervals of pulse waves of all four limbs in relation to age, gender, weight, height, heart rate, and blood pressure; to determine the PEP, ejection time (ET), UT, DT, PD, and ejection slope (ES) from the peripheral arterial pulse waveforms; to correlate these systolic and diastolic events with the age, gender, weight, height, waist and hip circumferences, heart rate, and blood pressure; and to compare the systolic and DT intervals between individuals with or without parental history of hypertension.

 Subjects and Methods



A total of 100 apparently healthy MBBS students, belonging to both genders, between the age groups of 18 and 21 years were included in this study after taking prior informed consent. Students with a history of hypertension, congenital or acquired cardiovascular diseases, and respiratory and renal diseases which may be detrimental to heart rate and blood pressure values were excluded from the study.

This study was conducted during the months of June–July 2018 after taking approval from the Institutional Review Board (Ref. no.: 2018/22/001).

Students' particulars, history, and demographic data were noted in a case report form. Anthropometric measurements such as weight and height were measured, and body mass index (BMI) was calculated.

Measurement of peripheral arterial pressures and determination of systolic and diastolic time intervals

A computer-based automated machine – PeriScope (Genesis Medical Systems, Hyderabad, Telangana, India) – was used for recording of peripheral arterial pressures [Figure 1]. This is a noninvasive method of blood pressure measurement. This instrument is present in the department of physiology of our medical college and was procured under Indian Council of Medical Ressearch (ICMR) Extramural Research Grant (IRIS ID: 2012-0836). The following parameters were recorded:{Figure 1}

Peripheral arterial pressure parameters (in all four limbs – right and left brachial and right and left posterior tibial): systolic blood pressure, diastolic blood pressure, pulse pressure, and mean arterial pressure [as shown in [Figure 2]Peripheral arterial pressure waveforms (in all four limbs – right and left brachial and right and left posterior tibial)Different time intervals such as PEP, ET, UT, DT, PD, and ES.{Figure 2}

Statistical analysis

The data obtained were analyzed using SPSS version 17.0 (SPSS Inc., Chicago, IL, USA). For analyzing the differences between the groups, independent sample t-test was used for scale variables. Correlation analysis was also performed on the data obtained. Statistical significance was fixed at P < 0.05.

 Results



One hundred MBBS graduate students, who were apparently healthy, both males and females, were enrolled for this study. Since some data of 2 students (1 male and 1 female) were missing, data analysis was done for the remaining 98 students (males: 49; females: 49).

[Table 1] shows the mean values of demographic and anthropometric details of the students. Independent sample t-test showed statistically significant differences between genders with weight, height, waist circumference, and waist–hip ratio.{Table 1}

[Table 2] gives the differences between males and females with respect to peripheral arterial pressure parameters in all four limbs. Independent sample t-test showed statistically significant differences between right arm systolic blood pressure, left arm systolic blood pressure, and left arm pulse pressure between males and females. No significant differences were found in the blood pressures of lower limbs between both the groups.{Table 2}

[Table 3] shows the differences between heart rate and cardiac time intervals between males and females in all four limbs. Statistically significant differences using independent sample t-test were present between ET in the right arm, left arm, and right ankle; UT [Figure 3] and ES [Figure 4] in all four limbs; and DT in the left arm between both the groups. The remaining time intervals did not show any statistically significant difference between males and females. Heart rate also did not vary significantly between the two groups.{Table 3}{Figure 3}{Figure 4}

Correlation statistics between different systolic and diastolic events with age, anthropometric parameters, heart rate, and mean arterial pressures between males and females is shown in [Table 4], [Table 5], [Table 6].{Table 4}{Table 5}{Table 6}

As the data obtained followed a normal distribution, Pearson's correlation statistics was done separately for both the groups.

[Table 4] shows the correlation between systolic and diastolic events with age and anthropometric parameters in males and females. Age did not show any correlation with systolic and DT intervals in both males and females as it was in a narrow range. RAES correlated negatively with weight and hip circumferences in females and positively with height in males. LAES correlated negatively with weight and hip circumferences in females. Right ankle ejection time correlated positively with weight and waist circumferences in males. Right ankle upstroke time (RAnUT) correlated negatively with waist circumference in females. Left ankle ejection time (LAnET) correlated positively with weight in males. The above mentioned correlations between parameters were statistically significant.

As shown in [Table 5], ES in all four limbs in both males and females does not show any correlation with heart rate. UT is negatively correlated with heart rate in all four limbs in males. In females, UT shows a negative correlation with heart rate in both upper limbs and right ankle.

The results shown in [Table 6] can be interpreted as follows:

Right arm diastolic time, left arm ejection time, right ankle diastolic time, left ankle upstroke time, and PD (in all four limbs) showed a significant negative correlation with MAP in all four limbs in males. No such statistically significant correlation was obtained in the female groupRight arm ejection slope showed a statistically significant negative correlation with MAP in all four limbs in males whereas only in lower limbs in femalesLeft arm ejection slope showed a statistically significant negative correlation with MAP in right upper and lower limbs in males and in all four limbs in the female groupPEP, right arm upstroke time, RAnUT, right ankle ejection slope, LAnET, and left ankle ejection slope did not show any significant correlation with mean arterial pressures in all four limbs in males and females.

Comparison of cardiac time intervals with a parental history of hypertension

A comparison of cardiac time intervals with a parental history of hypertension was done using one-way analysis of variance (ANOVA). Based on the parental history of hypertension, the students were grouped into four: Group 1: only father, Group 2: only mother, Group 3: both, and Group 4: none. One-way ANOVA done on this subgroup data did not show any statistical significance between cardiac time intervals and parental history of hypertension.

 Discussion



Numerous studies have been conducted on the significance of cardiac time intervals and their indispensability in assessing left ventricular function. Many others have also attempted to understand the effects that anthropometric and demographic parameters may have on cardiac time intervals. This study was conducted with the aim of correlating the cardiac time intervals with age, anthropometric parameters, heart rate, and blood pressure in young adults.

Our study did not show any correlation between age and cardiac time intervals as the students' age was in a narrow range of 19–21 years, unlike in the study conducted by Biering-Sørensen et al. who measured cardiac time intervals using tissue Doppler imaging M-mode in 974 individuals and studied their relationship with established measures of systolic and diastolic function; they found significant variations in cardiac time intervals with gender and age.[5]

PEP did not have any significant correlation with anthropometric parameters. Heart rate showed a statistically significant negative correlation with UT between both genders. This was in contrast to the results obtained by Wanderman et al.[6] who conducted a study in 1980 on 147 healthy adolescents and on regression analysis found that heart rate was the only variable consistently related to electromechanical systole (QS2), LVET, and PEP.

UT and ES recorded in all four limbs were the two time intervals which showed statistically significant differences between males and females. Since UT (which is the time recorded from the onset to the peak of arterial pulse waveform) is considered as an important index for peripheral artery disease, its increased value at a young age can be taken as a warning for developing the disease later in life.[7] UT also showed a negative correlation with heart rate in all four limbs in males and in upper limbs in females. This was in sync with previous reports confirming the negative correlation.[8],[9]

ES gives the overall measure of left ventricular function.[10] We correlated ES of all four limbs with the corresponding mean arterial pressures. It was found that mean arterial blood pressure recorded in all four limbs showed a significant negative correlation with right arm ES in males and left arm ES in females. This difference could not be attributed to any reason whatsoever.

 Conclusion



We conclude that gender, height, weight, waist and hip circumferences, and blood pressure influence the cardiac time intervals. Therefore, these time intervals should be adjusted for gender and anthropometric parameters in deriving the inference for left ventricular performance. Moreover, abnormal cardiac time intervals at young age should prompt for a thorough cardiovascular examination as it indirectly reflects impairment in left ventricular function. Analysis of cardiac time intervals can be done complementarily with recording of heart rate variability to better understand cardiac autonomic regulation.[11]

Arterial stiffening as seen in atherosclerosis is an important risk factor for hypertension and cardiovascular diseases (CVDs). Furthermore, decreased ventricular compliance or ventricular contractility leads to heart pump failure. Keeping these facts in mind, in young adults, changes in cardiac time intervals as assessed by the pulse wave analysis may be used as early signs of decreasing compliance in the cardiovascular system, which can warrant early lifestyle intervention so that the development of hypertension and CVD will be prevented or deferred.

Ethics clearance

Ethics clearance was obtained from the Institutional Review Board of our medical college (Ref. no.: 2018/22/001).

Financial support and sponsorship

This study was partly supported by Indian Council of Medical Research (ICMR) Short Term Studentship awarded to Ms. Sadiqua Sadaf (ICMR STS REFERENCE ID: 2018-05759) and ICMR Extramural Research Grant (IRIS ID: 2012-0836; Principal Investigator: Dr. Mohammed Abdul Hannan Hazari).

Conflicts of interest

There are no conflicts of interest.

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