Chi-In Lo

PATTERN AND IMPACT OF ALTERED REGIONAL MYOCARDIAL EXCURSION ON GLOBAL VENTRICULAR PERFORMANCE AFTER FIRST-TIME ACUTE ANTERIOR WALL MYOCARDIAL INFARCTION BY REAL-TIME THREE-DIMENSIONAL ECHOCARDIOGRAPHY

SUMMARY Background The regional wall motion score index obtained by two-dimensional echocardiography in myocardial infarction (MI) has a significant impact on left ventricular (LV) global contractility and is of extraordinary prognostic value, whereas data regarding real-time three-dimensional echocardiography (RT-3DE) are lacking. We sought to clarify the relationship between RT-3DE and LV contractility in patients after MI. Methods RT-3DE was performed in 50 patients with anterior wall acute myocardial infarction and 30 normal controls. Global (16 segments) and regional ring-based LV systolic excursions were analyzed offline using the commercially available software Q-Lab version 5.0. The correlations between the LV global and regional systolic excursions and the global LV contractile performance were examined in the MI patients, and further compared with the control group. Results The global and regional (basal and middle ring-based) LV systolic excursions were lower in the MI patients (age, 61.8 ± 13.1 years) than in the normal controls (age, 40.0 ± 15.4 years). Global excursion showed inverse linear relationships with LV end-systolic volume ( r =-0.26, p r =-0.22, p p = 0.08) and stroke volume ( p = 0.49). Conclusion Regional wall motion abnormalities quantified by RT-3DE are clinically convenient and feasible in both MI patients and the normal population. This rapid and objective quantification may also help discriminate abnormal from normal regional and global functions after infarction and, therefore, has the potential to be an attractive solution for clinical diagnosis.

The associations among co-morbidity, cardiac geometries and mechanics in hospitalized heart failure with or without preserved ejection fraction

ABSTRACT Background: The associations among chronic health conditions, ventricular geometric alterations or cardiac contractile mechanics in different phenotypes heart failure (HF) remain largely unexplored. Methods: We studied 438 consecutive hospitalized patients (mean age: 64.9 ± 16.6 years, 52.5% female) with or without clinical evidence of HF. We examined the associations among clinical co-morbidities, LV geometries and systolic mechanics in terms of global myocardial strains. Results: Increasing clinical co-morbidities was associated with greater LV mass, worse longitudinal deformations and higher proportion of admission with HF diagnosis, which was more pronounced in HFpEF (from 6.4% to 40.7%, X2 < 0.001). The independent association between co-morbidity burden and longitudinal functional decay remained unchanged after adjusting for age and sex for all admissions and in HFpEF (Coef: 0.82 & 0.71, SE: 0.13 & 0.21, both p≤0.001). By using co-morbidity scores, the area under receiver operating characteristic curves (AUROC) in identifying HFpEF was 0.71 (95% CI: 0.65 to 0.77), 0.64 (95% CI: 0.58 to 0.71) for HFrEF and 0.72 for both (95% CI: 0.67 to 0.77). Co-morbidity burden superimposed on LV mass index and LV filling pressure (E/E’) further expanded the AUROC significantly in diagnosing both types HF (c-statistics from 0.73 to 0.81, p for ΔAUROC: 0.0012). Conclusion: Chronic health conditions in the admission population were associated with unfavorable cardiac remodeling, impair cardiac contractile mechanics and further added significantly incremental value in HF diagnosis. Our data suggested the potentiality for better cardiac function by controlling baseline co-morbidities in hospitalized HF patients, especially HFpEF. Abbreviations: CAD: coronary artery disease; CKD: chronic kidney disease; DT: deceleration time; eGFR: Estimated glomerular filtration rate; HF: heart failure; IVRT: iso-volumic relaxation time; LV: left ventricular; LVEF: left ventricular ejection fraction; RWT: relative wall thickness; TDI: Tissue Doppler imaging

THE CLINICAL USEFULNESS AND UTILIZATION OF TISSUE DOPPLER IMAGING, LONGITUDINAL AND CIRCUMFERENTIAL STRAIN AND STRAIN RATE IN THE DIAGNOSTIC ACCURACY FOR DIFFERENT PHENOTYPES OF HEART FAILURE

Tissue Doppler imaging (TDI) is a sensitive tool in identifying diastolic dysfunction. Recent progresses in myocardial deformation imaging has enabled early detection of subclinical systolic dysfunction. Head-to-head comparison and optimal cut-off by these measures for different heart failure

Determinants of Left Ventricular Geometric Alterations and Related Clinical and Metabolic Factors in a General Population

SUMMARY Background: Left ventricular (LV) remodeling has been shown to impart prognostic significance in previous studies. However, the underlying exact mechanisms involved and interactions between LV geometry alterations and age with other clinical and biochemical variables in general population have not been well established. Methods: A total of 406 consecutive subjects were enrolled in a health evaluation center-based population study (mean age, 51.5 ± 10.9 years; 42% women). Data including baseline characteristics, echocardiography, biochemistry and biomarkers were all collected and evaluated. Univariate and multivariate regression analysis was performed to test the relationship between relative wall thickness (RWT) and other variables. We also divided the subjects into older and younger groups, compared RWT between the two groups, and analyzed the distribution of LV geometry in these groups. Results: The prevalence of diabetes and hypertension in our study population was relatively small (11.6% and 16.5%, respectively). The most common type of LV geometry in our study was normal (67.5%) and concentric remodeling (30.3%) compared with a relatively small proportion of concentric LV hypertrophy (1.5%) and eccentric hypertrophy (< 1%). Of all 406 subjects evaluated, age, uric acid, height, systolic blood pressure and serum insulin level were all independent factors associated with RWT in a multivariate regression model. Conclusion: In our study, we revealed that aging, together with baseline blood pressure and serum biochemistries, were associated with LV geometric alterations. These data suggest that the LV remodeling process actually involves dynamic and complex interactions with multiple metabolic factors in an unselected general population in Taiwan. (International Journal of Gerontology 2009; 3(1): 66-74)

The relationship of renal function to segmental vascular stiffness, ankle-brachial index, and peripheral artery disease

The authors consecutively assessed various arterial pulse‐wave velocity (PWV) indices and ankle‐brachial index (ABI) by an automatic device (VP2000, OMRON Health Care Co. Ltd., Kyota, Japan) in outpatients with ≥ 1 cardiovascular risk. PAD was defined as ABI ≤ 0.9. Among 2309 outpatients (mean age 62.4 years), worse renal function was associated with higher brachial‐ankle PWV, heart‐carotid PWV, heart‐femoral PWV (hf‐PWV), and lower ABI (all P < .001). Multivariate regression models showed independent associations between lower eGFR, lower ABI (Coef: 0.42 & 0.41 for right and left), higher hf‐PWV (Coef: −11.4 [95% CI: −15.4, −7.3]) and greater PAD risk (adjusted OR: 0.83 [95% CI: 0.76, 0.91], all P < .05). eGFR set at 77 mL/min/1.73m2 was observed to be useful clinical cutoff (c‐statistics: 0.67) for identifying PAD (P for ΔAUROC: .009; likelihood X2: 93.82 to 137.43, P < .001) when superimposed on clinical risks. This study suggested early renal insufficiency is tightly linked to region‐specific vascular stiffness and PAD.

Evaluation of the Accuracy of ECG Captured by CardioChip through Comparison of Lead I Recording to a Standard 12-Lead ECG Recording Device

Background Remote cardiac rhythm monitoring and recording, using hand-carried electrocardiogram (ECG) device had been widely used in telemedicine. The feasibility and accuracy analysis on the data recorded by a new miniature ECG system-on-chip (SoC) system has not been explored before. Methods This study evaluated the accuracy of the ECG recordings captured by CardioChip - a single-channeled, low-powered, miniature ECG SoC designed for mobile applications; comparing against Philips Pagewriter Trim III - a Food and Drug Administration certified, widely-used standard 12-lead ECG recording device, within Mackay Memorial Hospital in Taiwan. Results Total of 111 participants, age ranging from 39 to 87years old [mean age: 61.2 ± 13.4, 57 male (51.3%)] were enrolled. Two experienced cardiologists rated and scored the ECG morphology to be the same between the two devices, while CardioChip ECG was more sensitive to baseline noise. R-peak amplitudes measured both devices using single lead information (CardioChip ECG vs. Lead 1 in standard 12-lead ECG) showed statistical consistency. Offline analysis of signal correlation coefficients and coherence showed good correlation with both over 0.94 in average (0.94 ± 0.04 and 0.95 ± 0.04, respectively), high agreement between raters (94% agreement) for detecting abnormal cardiac rhythm with excellent R-peak amplitude (r = 0.98, p < 0.001) and PR interval (r = 0.91, p < 0.001) correlations, indicating excellent correlation between ECG recordings derived from two different modalities. Conclusions The results suggested that CardioChip ECG is comparable to medical industry standard ECG. The future implementation of wearable ECG device embedded with miniature ECG system-on-chip (SoC) system is ready for clinical use, which will potentially enhance efficacy on identifying subjects with suspected cardiac arrhythmias.