Indexing of Left Atrial Volume by various body size parameters in the Indian non-obese normal subjects: Is there an incremental value ?

BACKGROUND: Left atrial (LA) volume indexing for body surface area (BSA) is the common practice. Since LA volume index is of cardiovascular pathophysiologic significance, it is suggested that indexing for other body size parameters be explored to evaluate a more appropriate alternative method. The aims of this study were to find normal and the best cutoff values for LA volume indexed for multiple body size parameters in normal Indian subjects. METHODS: Data from the multicentric prospective INDEA study conducted through 2018 to 2020 was reviewed and subjects without known cardiac disease and completely normal echocardiograms that had the left atrial volume (LAV) measured by biplane Simpson's method were included. LAV was indexed by BSA (ml/m2), by height (LAV/m), by height raised to exponent 1.72 (mL/m 1.72 and 2.7 (ml/m2.7), by body weight, by ideal body weight (IBW), by ideal body surface area (IBSA) and by height squared (ml/h2). RESULTS: A total of 1046 healthy volunteers (382 female, 38%), mean age 38 ± 10.4 years (range 30-48 years) and body mass index 23.6 kg/m2 (22-25 kg/m2) were analyzed. Mean and normal values were: LAV/BSA 18.7 + 3.15 ml/m2 (range 15-21 ml/m2), LAV/ht 26.0 ± 4.5 ml/m, (range 17-35 ml/m), LAV/ht2 16 ± 2.8 ml/m2 (range 10.4-21.6 ml/m2) and LAV/ht2.7 8.71 ± 2.2 ml/m2.7 (range 6.98-13.58 ml/m2.7). Using ROC curve analysis, LAV/h 1.72 had the highest AUC and the best predictive value to identify LA enlargement but not very different from LAV/BSA. Ideal BSA and ideal body weight as a denominator did not provide any incremental value. CONCLUSION: Normal values for LAV indexed for height, weight, body surface area by three different methods of height as an allometric parameter are described in normal Indian individuals. We reinforce that LA volume indexation for BSA is an acceptable and robust method in non-obese Indian subjects. Indexing for height 1.72 is probably slightly superior method to evaluate LAV.

Mitral Annulus Disjunction and Arrhythmic Mitral Valve Prolapse: Emerging Role of Cardiac Magnetic Resonance Imaging in the Workup.

Mitral valve prolapse is a commonly described entity with a highly variable and benign course. However, it is associated with ventricular arrhythmias and sudden cardiac death in a small subset of patients. Recent studies have yielded insight into myocardial mechanics and the causation of ventricular arrhythmias in these groups of patients. Mitral annular disjunction (MAD) characterized by detachment of mitral annulus from left ventricular myocardium is associated with morphological and functional remodeling of the left ventricular myocardium. Resultant fibrosis acts as a substrate of ventricular arrhythmia and sudden cardiac death. We present two such cases of arrhythmic mitral valve prolapse associated with MAD. Cardiac magnetic resonance imaging provides excellent morphological information and also helps in the assessment of fibrosis.

Myocardial Strain Imaging Using Feature Tracking Method of Cardiac MRI: Our Initial Experience of This Novel Parameter as an Additional Diagnostic Tool.

Background Left ventricular ejection fraction (LVEF) is used as quantitative parameter to evaluate myocardial function. However, interobserver variation, limited reproducibility, and dependence on pre-load and after-load reduces its accuracy. The fall in LVEF occurs very late, when myocardial dysfunction is already advanced. Myocardial strain measurements (especially global longitudinal strain) is a new parameter to detect myocardial dysfunction before derangements in LVEF. The aim of this article is to share our experience of this novel diagnostic tool. Methods Feature tracking method of strain assessment is performed using routine long and short axis cine images of cardiac MRI (CMR). Dedicated post-processing CMR software can perform off-line analysis and provide results in form of color-coded maps, percentage values as well as strain over time curve for each myocardial segments. Results Global longitudinal strain (GLS) is more sensitive than LVEF and can identify sub-clinical left ventricular (LV) dysfunction in various cardiomyopathies. It is also an important prognostic marker in serial assessment of heart failure patients. Regional differences in strain parameters can provide clues in hypertrophic cardiomyopathy as well as amyloidosis. GLS is recommended as routine measurement in patients undergoing chemotherapy to detect LV dysfunction prior to fall in LVEF. Strain imaging can be applied to guide placement of the LV pacing lead in patients receiving cardiac resynchronization therapy. More clinical data is needed to evaluate its role in ischemic heart disease. Conclusion Strain imaging can identify LV dysfunction earlier than conventional methods and this opens a new perspective in risk stratification and therapeutic decision-making of various cardiac pathologies.

Normative values of cardiac chamber dimensions and global longitudinal strain in Indians: the Indian Normative Data of Echocardiography Analyzed (INDEA) study.

Ethnic-specific normal reference ranges for various echocardiographic measurements are essential for accurate diagnostic interpretation and clinical decision-making. Unfortunately, such normative data for Indians is lacking. A total of 880 healthy volunteers (mean age 39.7 ± 12.3 years, 63.8% men) from six centers across different regions of India were enrolled in this study. Comprehensive transthoracic echocardiographic study was performed in all subjects, in accordance with the existing guideline recommendations. Cardiac chamber dimensions [Left ventricular (LV) end-diastolic diameter and volume; right ventricular (RV) basal diameter, left atrial volume] were obtained and indexed to body surface area. LV ejection fraction, LV global longitudinal strain (LVGLS) and measures of RV systolic function were also obtained. The subjects were divided into 3 age groups (35 years or less, 36-55 years and 56 years or above) for analysis. Age- and gender-specific reference values for various clinically relevant echocardiographic parameters were derived. Compared with women, men had larger cardiac chamber dimensions and volumes, but not when indexed. In contrast, the women had higher LV systolic function, but right ventricular systolic function was not different. The indexed LV volumes in our study were much smaller than those recommended in the American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI) 2015 chamber quantification guidelines but were similar to those reported in the Indian patients included in the recent World Alliance Societies of Echocardiography (WASE) Normal Values Study. LVGLS was also comparable with the WASE data. INDEA study is the first, multi-centric study to provide normal echocardiographic references values for Indian adults. Our findings underscore the need to follow India-specific reference values, instead of those recommended by the ASE/EACVI, which are largely applicable to the western populations.

Myocardial Work Index: A Novel Method for Assessment of Myocardial Function in South Asian Recreational Athletes.

PURPOSE: We used a novel noninvasive method based on speckle-tracking echocardiography to evaluate myocardial performance in South Asian recreational athletes who completed a half marathon. METHODS: Transthoracic echocardiography was performed on 24 recreational athletes 48 hours before they took part in a half marathon (premarathon), within 2 hours of half marathon completion (postmarathon), and 72 hours after completion. Clinical, laboratory, and echocardiographic variables were collected. Speckle-tracking echocardiography was performed in all subjects to characterize myocardial mechanics. RESULTS: Mean age of participants was 41.8 ± 7.4 years, and 23 (95.8%) were male. No subject had a prior history of coronary artery disease. Significant changes in pre- and postmarathon values suggested myocardial injury, including an increase in mean brain natriuretic peptide (BNP), an increase in left atrial volume, and an overall reduction in peak left ventricular global longitudinal strain. All subjects had a similar value of global work index, the average myocardial work, premarathon. Global work index did not change in 11 patients (Group 1), and global work index increased in 13 patients (Group 2) immediately postmarathon. Group 2 patients were noted to have higher heart rate, lower end-diastolic and end-systolic volumes, and higher BNP levels, suggesting myocardial stress. CONCLUSIONS: South Asian athletes completing a half marathon exhibited two different responses to the cardiac stress of the half marathon, as outlined by the use of myocardial work indices, a novel method for assessing cardiac performance.

Prevention of sudden cardiac death in athletes, sportspersons and marathoners in India.

The annual incidence of sudden cardiac death (SCD) in athletes is significantly lower than the general population. However, when SCD occurs in an athlete during sporting event or training, it sends shockwaves in the society and raises questions about cardiovascular effects of sports and exercise. This document reviews the causes and mechanism of SCD in sports and exercise in young and older athletes. In the Indian context, we suggest a 'pre-participation screening' of young and older athletes and consider a 'supervised, graded exercise regime' for the uninitiated, older sports participant. Finally, the document proposes medical infrastructure required to successfully revive a victim of sudden cardiac arrest during a sporting event.

Adaptive filtering for suppression of respiratory artifact in impedance cardiography.

Impedance cardiography is a noninvasive technique, based on sensing the variation in the electrical impedance of the thorax caused by variation in the blood volume during the cardiac cycle, for monitoring the stroke volume and some other cardiovascular indices. Respiratory and motion artifacts cause baseline drift in the sensed impedance waveform, particularly during or after exercise. This paper presents an LMS-based adaptive filtering technique for suppression of respiratory artifact for improving the estimation of the indices without smearing the beat-to-beat variations. It uses a reference signal, closely related to the respiratory artifact, obtained by a least-squares approximation based B-spline fitting on the contaminated impedance cardiogram in synchronism with the respiratory phases. The technique is evaluated on signals with simulated artifacts and on signals from nine healthy subjects and five patients with cardiovascular disorders. The values of the stroke volume, estimated on beat-to-beat basis, after suppression of respiratory artifact showed a good agreement with those from Doppler echocardiography.

Segmentation of left ventricle in short-axis echocardiographic sequences by weighted radial edge filtering and adaptive recovery of dropout regions.

In this paper, we present a weighted radial edge filtering algorithm with adaptive recovery of dropout regions for the semi-automatic delineation of endocardial contours in short-axis echocardiographic image sequences. The proposed algorithm requires minimal user intervention at the end diastolic frame of the image sequence for specifying the candidate points of the contour. The region of interest is identified by fitting an ellipse in the region defined by the specified points. Subsequently, the ellipse centre is used for originating the radial lines for filtering. A weighted radial edge filter is employed for the detection of edge points. The outliers are corrected by global as well as local statistics. Dropout regions are recovered by incorporating the important temporal information from the previous frame by means of recursive least squares adaptive filter. This ensures fairly accurate segmentation of the cardiac structures for further determination of the functional cardiac parameters. The proposed algorithm was applied to 10 data-sets over a full cardiac cycle and the results were validated by comparing computer-generated boundaries to those manually outlined by two experts using Hausdorff distance (HD) measure, radial mean square error (rmse) and contour similarity index. The rmse was 1.83 mm with a HD of 5.12 ± 1.21 mm. We have also compared our results with two existing approaches, level set and optical flow. The results indicate an improvement when compared with ground truth due to incorporation of temporal clues. The weighted radial edge filtering algorithm in conjunction with adaptive dropout recovery offers semi-automatic segmentation of heart chambers in 2D echocardiography sequences for accurate assessment of global left ventricular function to guide therapy and staging of the cardiovascular diseases.

Transcatheter closure of ruptured sinus of Valsalva aneurysm using the Amplatzer duct occluder in a critically ill post-CABG patient.

Ruptured sinus of Valsalva aneurysm is a rare but well recognized clinical entity. These patients develop congestive heart failure due to biventricular increases in volume as a result of sudden aortocardiac shunting. Traditionally, surgical repair has been the mainstay of therapy. We report a case of a ruptured sinus of Valsalva aneurysm that was successfully closed percutaneously using the Amplatzer duct occluder in a critically ill patient operated on previously for coronary artery disease and presenting with acute congestive heart failure.