Chun-Na Jin

Beyond auscultation: Acoustic cardiography in clinical practice

Cardiac auscultation by stethoscope is widely used but limited by low sensitivity and accuracy. Phonocardiogram was developed in an attempt to provide quantitative and qualitative information of heart sounds and murmurs by transforming acoustic signal into visual wavelet. Although phonocardiogram provides objective heart sound information and holds diagnostic potentials of different heart problems, its examination procedure is time-consuming and it requires specially trained technicians to operate the device. Acoustic cardiography (AUDICOR, Inovise Medical, Inc., Portland, OR, USA) is a major recent advance in the evolution of cardiac auscultation technology. The technique is more efficient and less operator-dependent. It synchronizes cardiac auscultation with ECG recording and provides a comprehensive assessment of both mechanical and electronic function of the heart. The application of acoustic cardiography is far beyond auscultation only. It generates various parameters which have been proven to correlate with gold standards in heart failure diagnosis and ischemic heart disease detection. Its application can be extended to other diseases, including LV hypertrophy, constrictive pericarditis, sleep apnea and ventricular fibrillation. The newly developed ambulatory acoustic cardiography is potentially used in heart failure follow-up in both home and hospital setting. This review comprehensively summarizes acoustic cardiographic research, including the most recent development.

Dynamic assessment of the changing geometry of the mitral apparatus in 3D could stratify abnormalities in functional mitral regurgitation and potentially guide therapy.

INTRODUCTION In functional mitral regurgitation (FMR), effective regurgitant orifice area (EROA) displays a dynamic pattern. The impact of dynamic changes of annulus dysfunction and leaflets tenting on phasic EROA was explored with real-time three-dimensional transesophageal echocardiography (RT3D-TEE). METHODS RT3D-TEE was performed in 52 FMR patients and 30 controls. Mitral annulus dimensions and leaflets tenting were measured throughout systole (TomTec, Germany). Phasic EROA was measured by proximal isovelocity surface area (PISA) method. RESULTS Mitral annulus had the minimal area and an oval shape with saddle configuration during early systole in controls, which enlarged and became round and flattened towards mid and late systole (P<0.05). In contrast, annulus in FMR was significantly larger, rounder and flatter (P<0.001), which further dilated and became more flattened at late systole (P<0.05 vs control). Leaflet tenting height in FMR decreased in mid systole and remains unchanged towards late systole. The leaflet tenting volume peaked at early and late systole with a mid-systolic trough in both FMR and controls. But tenting volume of patients with FMR was significantly larger than that of controls (all P<0.001 vs control in whole systole). Further analysis demonstrated that early tenting volume (β value=0.053, P<0.05) was a predictor of early EROA, whereas late tenting volume (β value=0.031, P<0.05) and late annular displacement velocity were predictors of late EROA. CONCLUSIONS The early and late peak EROAs of FMR was primarily contributed by tenting volume at early systole and late systole respectively. These findings would be of value to consider in interventions aimed at reducing the severity of FMR.

Automated quantification of mitral valve anatomy using anatomical intelligence in three-dimensional echocardiography

BACKGROUND Quantitative analysis of mitral valve morphology with three-dimensional (3D) transesophageal echocardiography (TEE) provides anatomic information that can assist clinical decision-making. However, routine use of mitral valve quantification has been hindered by tedious workflow and high operator-dependence. The purpose of this paper was to evaluate the feasibility, accuracy and efficiency of a novel computer-learning algorithm using anatomical intelligence in ultrasound (AIUS) to automatically detect and quantitatively assess the mitral valve anatomy. METHODS A novice operator used AIUS to quantitatively assess mitral valve anatomy on the 3D TEE images of 55 patients (33 with mitral valve prolapse, 11 with functional mitral regurgitation, and 11 normal valves). The results were compared to that of manual mitral valve quantification by an experienced 3D echocardiographer and, in the 24 patients who underwent mitral valve repair, the surgical findings. Time consumption and reproducibility of AIUS were compared to the manual method. RESULTS AIUS mitral valve quantification was feasible in 52 patients (95%). There were excellent agreements between AIUS and expert manual quantification for all mitral valve anatomic parameters (r=0.85-0.99, p<0.05). AIUS accurately classified surgically defined location of prolapse in 139 of 144 segments analyzed (97%). AIUS improved the intra- [intraclass-correlation coefficient (ICC)=0.91-0.99] and inter-observer (ICC=0.86-0.98) variability of novice users, surpassing the manual approach (intra-observer ICC=0.32-0.95; inter-observer ICC=0.45-0.93), yet requiring significantly less time (144±24s vs. 770±89s, p<0.0001). CONCLUSION Anatomic intelligence in 3D TEE image can provide accurate, reproducible, and rapid quantification of the mitral valve anatomy.

The prevalence and prognosis of resistant hypertension in patients with heart failure.

Background Resistant hypertension is associated with adverse clinical outcome in hypertensive patients. However, the prognostic significance of resistant hypertension in patients with heart failure remains uncertain. Methods and Results The 1 year survival and heart failure re-hospitalization rate of 1288 consecutive patients admitted to a university hospital for either newly diagnosed heart failure or an exacerbation of prior chronic heart failure was analyzed. Resistant hypertension was defined as uncontrolled blood pressure (>140/90 mmHg) despite being compliant with an antihypertensive regimen that includes 3 or more drugs (including a diuretic). A total of 176 (13.7%) heart failure patients had resistant hypertension. There was no difference in all cause mortality, cardiovascular mortality, and heart failure related re-hospitalization between patients with versus without resistant hypertension. Diabetes [hazard ratio = 1.62, 95% confidence interval = 1.13–2.34; P = 0.010] and serum sodium >139 mmol/L (hazard ratio = 1.54, 95% confidence interval = 1.06–2.23; P = 0.024) were independently associated with resistant hypertension. Patients with resistant hypertension had a relatively higher survival rate (86.9% vs. 83.8%), although the difference was not significant (log-rank x2 = 1.00, P = 0.317). In patients with reduced ejection fraction, heart failure related re-hospitalization was significantly lower in patients with resistant hypertension (45.8% vs. 59.1%, P = 0.050). Conclusions Resistant hypertension appears to be not associated with adverse clinical outcome in patients with heart failure, in fact may be a protective factor for reduced heart failure related re-hospitalization in patients with reduced ejection fraction.

The healthcare burden of hypertension in Asia

As the leading global risk for mortality, hypertension (HT) is a common healthcare problem in the world. The total number of patients with HT is likely to grow in the next few decades as the population age and the prevalence of obesity and diabetes increase. HT, as a major modifiable risk factor for cardiovascular disease, results in more deaths than any other risk factors, including diabetes and cigarette smoking. High prevalence, inadequate awareness, suboptimal treatment and low rate of achieving guideline-recommended target blood pressure control are key factors leading to severe cardiovascular complications that impose a heavy socioeconomic burden, especially in developing countries. Asia is the worlds largest and most populous continent with approximately 4.3 billion people, hosting 60% of the world’s current human population, and has a high growth rate. Asia differs very widely from the West with regard to ethnic groups, cultures, environments, economics, historical ties and government systems. Therefore, the purpose of this review is to comprehensively summarise the epidemiology, treatment practice and the status of control of HT in different Asian countries in order to guide the future prevention and management in this part of the world.

AUTOMATED QUANTIFICATION OF MITRAL VALVE ANATOMY FROM TRANSESOPHAGEAL THREE-DIMENSIONAL ECHOCARDIOGRAPHY: VALIDATION AGAINST MANUAL MEASUREMENT

Quantification of mitral valve anatomy (MVQ) with 3D TEE provides precise anatomic information of the MV that improves our understanding of disease mechanism and may aid in surgical decision-making. However, integration of MVQ into routine clinical practice has been limited by the time-consuming