Left atrial size and function in a South Asian population and their potential influence on the risk of atrial fibrillation

Background: South Asians have a low prevalence of atrial fibrillation (AF) compared with Caucasians despite having a higher prevalence of conventional risk factors for the arrhythmia. The reason for this disparity is uncertain but may be due to ethnic differences in atrial morphology. This study examines the association between ethnicity and left atrial (LA) size and function in South Asian and Caucasian subjects using the reference technique of cardiovascular magnetic resonance imaging (MRI). Hypothesis: South Asians have smaller LA size and therefore increased LA function. Methods: Retrospective case‐control study of 60 South Asian and 60 Caucasian patients who had undergone a clinically indicated MRI between April 2010 and October 2017 and had been found to have a structurally normal heart. LA and left ventricular (LV) volume and function were assessed and compared between the ethnicities. Results: In comparison with Caucasians, South Asians had significantly lower minimum (27.7 ± 11.1 mL vs 34.9 ± 12.3 mL, P = 0.002) and maximum LA volumes (64.7 ± 21.1 mL vs 80.9 ± 22.5 mL, P < 0.001), lower LV end‐diastolic volume (P < 0.001), lower LV stroke volume (P < 0.001), and lower LV mass (P = 0.022) and these values remained significant after correcting for body surface area. Further analysis revealed that LA volume was independently associated with South Asian ethnicity. There was no difference in LA function between the ethnic groups. Conclusions: South Asians have reduced LA volumes and a proportionally smaller heart size in comparison to Caucasians. Smaller LA size may protect against the development of AF by reducing the risk of reentrant circuit formation and atrial fibrosis development

The Development of ST-Episode Detection in Holter Monitoring for Myocardial Ischemia

AbstractCurrently, cardiac arrhythmia is a major cause of life threatening. Electrocardiogram (ECG) is the most useful physiological signal that is used in clinical diagnosis. Some abnormalities of heart functions can be investigated from ECG morphology. Many research works present that the changing of ST-T complex is a crucial parameter related to myocardial ischemia. Therefore, this paper reports our progress in ST-episode detection using time domain analysis. The database used in this study is European ST-T database from Physionet. As the results, the performance of our proposed technique can correctly detect ST-episode with 91.37% of sensitivity

New echocardiographic predictors of clinical outcome in patients presenting with heart failure and a preserved left ventricular ejection fraction: a subanalysis of the Ka (Karolinska) Ren (Rennes) Study

International audienceOBJECTIVES: To identify electrocardiographic and echocardiographic predictors of mortality and hospitalizations for heart failure (HF) in the KaRen study. BACKGROUND: KaRen is a prospective, observational study of the long-term outcomes of patients presenting with heart failure and a preserved ejection fraction (HFpEF). METHOD: We identified 538 patients who presented with acute cardiac decompensation, a \textgreater100 pg/mL serum b-type natriuretic peptide (BNP) or \textgreater300 pg/mL N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration and a left ventricular ejection fraction (LVEF) \textgreater45%. After 4-8 weeks of standard treatment, 413 patients (mean age = 76 ± 9 years, 55.9% women) returned for analyses of their clinical status, laboratory screen, and detailed electrocardiographic and Doppler echocardiographic recordings. They were followed for a mean of 28 months thereafter. The primary study endpoint was time to death from all causes or first hospitalization for heart failure. RESULTS: Mean LVEF was 62.4 ± 6.9% and median NT-proBNP 1410 pmol/L. PR interval \textgreater200 ms was present in 11.2% of patients and 14.9% had a \textgreater120 ms QRS duration, with left bundle branch block in only 6.3%. Over a mean follow-up of 28 months, 177 patients (42.9%) reached a primary study endpoint, including 61 deaths and 116 hospitalizations for heart failure. After adjustment for age, gender, New York Heart Association class, atrial fibrillation history, creatinine, sodium, BNP, ejection fraction, and right ventricular fractional shortening, only E/e' remained as a predictor, with a hazard ratio = 1.49 and P = 0.0012. CONCLUSION: The incidence of hospitalizations for HF and deaths in KaRen was high and E/e' predicted adverse clinical outcomes. These observations should help in the risk stratification and therapy of HFpE

Impact of left ventricular volume/mass ratio on diastolic function

Aims To assess the impact of left ventricular (LV) volume/mass ratio on diastolic function parameters in subjects with dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) and healthy controls. Methods and results We performed echocardiography in 44 healthy controls, 35 HCM subjects, 29 DCM subjects with narrow QRS complex (DCM-n), and 27 DCM subjects with wide QRS complex (DCM-w). Mitral annulus velocity (Ea) and trans-mitral E-wave velocity were used to estimate time constant of isovolumic pressure decay (t). LV flow propagation velocity (Vp) and early intraventricular pressure gradient (IVPG) were derived from colour M-mode of LV inflow. We calculated LV twist and peak untwisting rate (UntwR) by speckle tracking. Mean LV volume/mass ratio was 0.34+ 0.09 mL/g in healthy controls, 0.15+0.06 mL/g in HCM, 0.6+ 0.2 mL/g in DCM-n, and 0.8+0.3 mL/g in DCM-w patients (P, 0.001 for all groups). Resting LV ejection fractions were 63+ 7, 64+ 8, 31+8, and 26+8%, respectively (P, 0.01 vs. controls for DCM groups). In a multivariate analysis, LV volume/mass rati