Cardiac morphometry in healthy young Indian adult males: An evaluation of chamber thickness and left ventricular cardiac mass

Rohit Aggarwal; Ruchi Gautam; Abdul Raheem Sheik

doi:10.4103/jasi.jasi_77_21

ORIGINAL ARTICLE

Year : 2022 | Volume : 71 | Issue : 3 | Page : 199-203

Cardiac morphometry in healthy young Indian adult males: An evaluation of chamber thickness and left ventricular cardiac mass

Rohit Aggarwal¹, Ruchi Gautam², Abdul Raheem Sheik¹
¹ Department of Radiology, 7 Airforce Hospital, Kanpur Cantonment, Kanpur, Uttar Pradesh, India
² Department of Radiology, Command Hospital Air Force (Bangalore), Bengaluru, Karnataka, India

Date of Submission	21-Apr-2021
Date of Decision	03-Jan-2022
Date of Acceptance	09-Jun-2022
Date of Web Publication	20-Sep-2022

Correspondence Address:
Dr. Abdul Raheem Sheik
Department of Radiology, 7 Airforce Hospital, Nathu Singh Road, Kanpur Cantonment, Kanpur - 208 004, Uttar Pradesh
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jasi.jasi_77_21

Abstract

Introduction: Measurement of cardiac chambers is an important tool in the assessment of cardiac disease. Cardiac imaging can be used for the accurate assessment of these parameters. The primary objective of this study is to estimate various clinically relevant cardiac measurements including the left ventricular (LV) myocardial mass using cardiac magnetic resonance imaging (CMRI). The secondary objective is to correlate these measurements with the patient's body mass index (BMI). Material and Methods: A descriptive cross-sectional observational study was done at a tertiary care hospital. A total of 100 healthy young Indian adult males between 18 and 30 years of age underwent cardiac MRI on a 1.5Tesla Magnetic Resonance Imaging scanner. The thickness of various cardiac chambers and LV cardiac mass was measured. The results were compared with BMI. Results: Mean left atrial wall thickness is 1.6 mm in End -systole (ES)) and 1.5 mm in end diastole (ED). Mean Right atrial thickness is 1.5 mm (ES) and 1.8 mm (ED). Mean left ventricular wall thickness is 17.7 mm in End -systole (ES)) and 10.9 mm in end diastole (ED). Mean Right ventricular thickness is 6.9 mm (ES) and 3.2 mm (ED). Mean interventricular wall thickness is 14/9.7 mm in ES and ED, respectively. LV cardiac mass is 119.97 g. There is weak-to-moderate association between cardiac chambers and BMI. Discussion and Conclusion: Assessment of cardiac chamber thickness and LV cardiac mass in healthy adults can be made using CMRI. These values can be used as baseline to compare with measurements in various diseases of the heart.

Keywords: Cardiac imaging techniques, heart diseases, magnetic resonance imaging, myocardium

How to cite this article:
Aggarwal R, Gautam R, Sheik AR. Cardiac morphometry in healthy young Indian adult males: An evaluation of chamber thickness and left ventricular cardiac mass. J Anat Soc India 2022;71:199-203

How to cite this URL:
Aggarwal R, Gautam R, Sheik AR. Cardiac morphometry in healthy young Indian adult males: An evaluation of chamber thickness and left ventricular cardiac mass. J Anat Soc India [serial online] 2022 [cited 2023 Mar 29];71:199-203. Available from: https://www.jasi.org.in/text.asp?2022/71/3/199/356497

Introduction

Diseases of the cardiovascular system (CVS) are the leading cause of mortality.^[1] Evaluation of the heart is an important component of CVS diseases, which has evolved over time from mere palpation and auscultation to advanced cardiac imaging. At present, standard structural evaluation of the heart comprises electrocardiography (ECG), echocardiography, and angiography. Cardiac magnetic resonance imaging (CMRI) of the heart has gained popularity in the recent past due to its excellent temporal and spatial resolution, lack of ionizing radiation, and noninvasiveness. Various diseases of CVS like hypertension cause structural changes in the size and morphologies of cardiac chambers.^[2] Accurate evaluation of these changes involves various measurements of cardiac chambers and their comparison with known values in the healthy population. Conventionally, the cardiac chambers are evaluated on echocardiography. However, its accuracy is operator dependent and affected by the shape of cardiac chambers and the availability of sufficient field of view (FOV). These limitations can be addressed by CMRI which allows standardized measurements of various cardiac chambers on a 3-Dimensional (3D) dataset. Most clinically, relevant cardiac chamber measurements are the thickness of various cardiac chambers and left ventricular (LV) myocardial mass. There is limited literature on normal values of these parameters, especially in the Indian population. Thus, the primary objective of this study is to estimate various clinically relevant cardiac measurements including the LV myocardial mass. The secondary objective is to correlate these measurements with the patient's body mass index (BMI).

Material and Methods

This study is a descriptive cross-sectional observational study. The study is conducted in a tertiary care hospital catering to population representing various states of India. A total of 100 healthy volunteering participants were enrolled in the study. All the participants were aged between 18–30 years of age. Participants with a known history of hypertension and cardiac disease were excluded from the study. The study conforms to widely accepted ethical principles guiding human research. The study design was approved by the institutional ethics committee. Informed written consent was obtained from all the participants after explaining the purpose of the study and methodology. Patients who were unable to undergo CMRI evaluation or who could not complete the study due to various reasons like claustrophobia were excluded from the study. Patients underwent CMRI evaluation on a Siemens, Magentom Avanto1.5 Tesla Magnetic Resonance Imaging (MRI) scanner (Siemens medical systems, Erlangen, Germany). ECG-gated cine imaging of the heart was done in three planes, namely short-axis (SA), vertical long axis, and horizontal long axis (four chamber view). For half-Fourier acquisition single-shot turbo spin-echo sequences, the following parameters used were Time to Relaxation (TR) = 750 mS, Time to Echo (TE) = 46 mS, and FOV 234 mm × 340 mm. For cine SA, the following parameters were used TR = 45 mS, TE = 1.3 mS, FOV = 276 mm × 340 mm. After the images were acquired, they were transferred to dedicated workstation (Leonardo^©). Images were analyzed by using the specific post-processing tool (Argus^©) available in the workstation.

The wall thickness of all four chambers was recorded. The left atrial (LA) and right atrial (RA) wall thickness were measured in four-chamber views [Figure 1]. The average of maximum anterior and posterior wall thicknesses was recorded in end-systole (ES) and end-diastole (ED) frames of the cine sequence. The ventricular thickness was measured on ES and ED frames of cine sequence [Figure 2] and [Figure 3]. The right ventricular (RV) thickness was measured by measuring the mean of free wall thickness. The LV wall thickness was measured on four-chamber views by taking the maximum wall thickness. The LV ventricular cardiac mass was calculated on ED image frames by manually drawing epicardial and endocardial borders [Figure 4]. The mean thickness of the interventricular septum (IVS) was also estimated in the systolic and diastolic phases. The myocardial mass was calculated automatically on the “Argus^®” by using estimated volume and predetermined assumed density of myocardium. The mean, range, and 95% confidence interval (CI) of the above-mentioned values were estimated. Statistical analysis was performed by estimating the Pearson correlation coefficient and statistical significance was estimated by taking a P < 0.05 as statistically significant. The estimated measurements were compared with similar studies in published literature.

Figure 1: Measurement of atrial thickness

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Figure 2: Measurement of ventricular and inter-ventricular septum thickness in end systole

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Figure 3: Measurement of ventricular and inter-ventricular septum thickness in end diastole

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Figure 4: Measurement of endocardial mass in ED. Measured value on Argus software: 124.32 gm

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Results

The demographic details and thickness of various cardiac chambers were recorded and tabulated. The demographic details of the participants including age, weight, BMI, pulse, systolic and diastolic blood pressure are tabulated in [Table 1]. The thickness (mean, range, and 95% CI) of various cardiac chambers, interventricular septal thickness, and LV myocardial mass are tabulated in [Table 2]. The various cardiac chamber measurements were correlated with BMI using the Pearson correlation coefficient to see the relationship with the BMI. The findings (r value and P value) are tabulated in [Table 3].

Table 1: The demographic details of subjects

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Table 2: Cardiac chamber thickness and myocardial mass

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Table 3: Correlation of body mass index with cardiac chamber measurements

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Discussion

The study evaluated the thickness of various cardiac chambers and IVS in ES and ED frames. The LV myocardial mass was also estimated. Further, the study examined the relationship between the chamber thicknesses and LV cardiac mass with the BMI of the participants. The findings of our study were compared with similar studies in the available literature.

The mean thickness of LA in our study was 1.6 mm in ES and 1.5 mm in ED. Various authors have studied the relationship between LA wall thickness in patients with cardiac arrhythmias, especially atrial fibrillation (AF). Imada et al. have studied the LA wall thickness (LAWT) in patients of AF (16 chronic AF and 17 paroxysmal AF) using CT scan.^[3] In their study, the mean thickness of the LA wall was 2.6 mm. They also observed thinning of the LA wall in the chronic AF group as compared to the paroxysmal AF group. Similarly, Nakamura et al. have studied LAWT in 186 participants belonging to chronic AF, paroxysmal AF and normal controls and observed that patients with paroxysmal AF have higher LAWT than chronic AF and healthy controls.^[4] The mean LAWT in healthy controls in their study was 1.9 ± 0.2 mm. The results compare well with our study (1.5–1.6 mm). They also observed that the transition from Paroxysmal AF to Chronic AF was more frequent in patients with LAT <2.4 mm than LAT ≥2.4 mm suggesting LAWT can be a useful predictor of transition from PAF to CAF. Pan et al. have studied LAWT in 180 patients undergoing Multidetector computed tomography (CT) evaluation for coronary artery disease.^[5] They observed that in the age group of 50–80 years, the LAWT increases with age and also observed the anterior wall thickness is consistently greater than the posterior wall thickness. In this study, the observed LAWT in population <40 years of age is 2.0 ± 0.9 mm (anterior wall) and 0.7 ± 0.2 mm (posterior wall). In the year 2019, Zuo et al. studied the relationship between the LAWT and response to catheter ablation in patients with persistent AF.^[6] They observed that there is a negative association between the LAWT and response to ablation and LA roof thickness >3.10 mm might be the predictor of poor response to ablation.

The mean RA wall thickness in our study was around 1.5 mm in ES and 1.8 mm in ED. This compares well with other studies. In a post-mortem study by Wolf CM et al. the mean RA thickness was 1.8 ± 0.4 mm.^[7] Varela et al. have used a novel MRI technique to non-invasively measure atrial wall thickness (AWT) in 10 healthy volunteers and 2 patients with AF.^[8] They generated a whole atrial AWT Atlas ^{More Details} and measured mean AWT using this atlas. The mean Right AWT in their study was 2.7 ± 0.7 mm in healthy controls and 3.1 ± 1.3 mm in patients of AF with structural heart disease. Similarly, another study by Ginami G et al. quantified the AWT on CMR.^[9] The observed RAWT in this study was 2.54 ± 0.87 mm. The difference in the AWT could be due to the difference in the method of estimation of AWT and the difference in the investigative modality used.

In our study, the mean free wall thickness of RV was 3.2 mm (ED). In a study by Foale et al. using echocardiography on 41 normal adults, the mean RV thickness in ED was 3–5 mm.^[10] In our study, the mean ES RV thickness was 6.9 mm (4.0–10.0 mm). Similarly, Prakash has studied the correlation between the echocardiography and necropsy findings of the RV wall thickness in ES and ED.^[11] In their study, the mean ED and ES RV wall thickness were 3.0 ± 0.92 cm and 5.1 ± 1.64 cm, respectively. These findings correlate well with our study.

The mean LV wall thickness in our study was 10.9 mm (ED) and 17.7 mm (ES). Haag et al. compared the LV wall thickness on CMRI in systole and diastole with 2-Dimensional (2D) echocardiography and digital subtraction angiography (DSA).^[12] They observed that MR overestimates the wall thickness as compared to 2D echo and DSA. Using CMR, Dawson et al. have studied age- and sex-related morphometric changes in the thickness of LV in 120 healthy volunteers.^[13] They studied these changes with respect to ES versus ED as well as trabeculated versus compacted segment. They observed that the total wall thickness is neither sex nor age dependent. Further, they observed that compacted layer thickens and trabeculated layers thins out with age. The compact layer is thicker in systole, in males and in participants above 40 years of age as compared to diastole, females and younger participants. The average wall thickness in this study was 9.7 mm (ED) and 14 mm (ES), respectively. The difference could be due to the difference in the method of estimation of LV wall thickness.

The mean IVS thickness in our study was 9.7 mm in ED and 14 mm in ES. In a study by Hergan et al., the normal measurement of IVS was calculated in 56 volunteers.^[14] In males, the mean IVS thickness in diastole was 9.9 ± 1.2 mm, while in systole, it was 13.6 ± 1.9 mm. The findings correlate well with our study. Lorenz et al. have done CMR of 75 healthy adults and proposed normative data on the mass and function of LV and RV.^[15] They also assessed the gender differences in these parameters. Sandstede et al. have studied LV and RV cardiac mass in 36 healthy volunteers of four different age and gender groups of 09 in each group.^[16] The mean cardiac mass in LV was 155 ± 18 g, respectively. These values compare well with our study (119.9 g). They also found no difference in the cardiac mass between >45 years and <45 years age groups but significant gender differences with cardiac mass being high in males. Bhambhani et al. have estimated LA and LV cardiac chamber measurements in 133 healthy Indian adults using 3D echocardiography.^[17] In their study, the estimated LV mass was 119.79 g ± 23.95 g. These findings match closely the findings of our study (119.97 ± 25.86 g). They also noted significant gender differences in the mean LV mass, but this difference disappeared after indexing the values for body surface area.

The association with BMI and various measured cardiac chamber thickness showed weak to moderate association (r-value ranging from 0.11–0.36) between various parameters, as shown in [Table 3]. There is significant correlation between Left cardiac chamber thicknesses and LV cardiac mass in our study. Similarly, Fuchs et al. studied normal values of cardiac chambers and LV mass in 569 healthy controls. They also observed a significant association between LV cardiac mass and BMI.^[18] However, in another study by Krishnan et al., no correlation was found between LV thickness and BMI.^[19]

The main strength of our study is the use of CMRI for the estimation of various cardiac chambers. CMRI is free from ionizing radiation. It is not operator dependent and not limited by the orientation and shape of the cardiac chambers in comparison to echocardiography. It is also not limited by the availability of scanning window and can be done without the use of contrast. Limited data are available studying the racial differences in cardiac mass and only two studies have been done in India till date to the knowledge of authors.^[17],[19] However, CMR has certain drawbacks. The resolution of CMRI is less as compared to CT scan thus the measurements done on MRI would be less accurate than cardiac CT measurement. Breathing artifacts can significantly compromise the quality of images, especially in patients with poor breath hold. The study did not assess the inter-observer and intra-observer variability. Previous similar studies have shown that this observer bias is not statistically significant. Nevertheless, the involvement of more than one observer and the calculation of inter- and intra-observer variability would have further improved the value of the study. The study included only the male population due to administrative convenience. The absence of data from female participants might preclude generalization to the entire population. We only studied the cardiac chamber thickness and cardiac mass in the 18–30 years of age group. A study representing a wide range of age groups would have improved the generalizability of the study. While estimating the LV cardiac mass in our study, the mass of the individual components of the LV free wall and IVS were not measured separately. This could have been useful in conditions like transposition of great arteries and hypertrophic constrictive cardiomyopathy.

Conclusion

Measurement of various cardiac chamber thicknesses and LV mass can be done reliably using CMRI. This study evaluated these values using CMRI which is more reliable than echocardiography. Data on India-specific normal values of these cardiac chamber measurements are valuable for evaluating the changes in various disease processes.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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