ABSTRACT
BACKGROUND: It is well acknowledged that left ventricular (LV) contractile performance affects LV relaxation via LV elastic recoil. Accordingly, we aimed to investigate whether global longitudinal strain (GLS), particularly longitudinal strain at LV apical segments at end-systole (ALS), obtained by 2-dimensional speckle-tracking echocardiography could be used to assess LV relaxation.MethodsâandâResults:We enrolled 121 patients with suspected or definite coronary artery disease in whom echocardiography and diagnostic cardiac catheterization were performed on the same day. We obtained conventional echo-Doppler parameters and GLS, as well as ALS prior to catheterization. LV functional parameters were obtained from the LV pressure recorded using a catheter-tipped micromanometer. In all patients, GLS and ALS were significantly correlated with the time constant τ of LV pressure decay during isovolumetric relaxation (r=0.63 [P<0.001] and r=0.66 [P<0.001], respectively). Receiver operating characteristic curve analysis for identifying impaired LV relaxation (τ ≥48 ms) revealed that ALS greater than -22.3% was an optimal cut-off value, with 81.7% sensitivity and 82.4% specificity. Even in patients with preserved LV ejection fraction, the same ALS cut-off value enabled the identification of impaired LV relaxation with 70% sensitivity and 87.5% specificity. CONCLUSIONS: The findings indicate that contractile dysfunction at LV apical segments slows LV relaxation via loss of LV elastic recoil, even in patients with preserved LVEF.
Subject(s)
Echocardiography , Heart Ventricles , Heart Ventricles/diagnostic imaging , Humans , Stroke Volume , Systole , Ventricular Function, LeftABSTRACT
Intra-cardiac shunt diseases may cause chronic ventricular volume overload, but extra-cardiac fistula could also cause high-output heart failure (HF). A patient presented with high-output HF and significant extra-cardiac shunt flow. Although the size and shape of the patient's left ventricle suggested dilated cardiomyopathy, considerable origins were not identified except for a high-flow fistula between the right subclavian artery and right internal jugular vein. Right heart catheter examination revealed inappropriately high cardiac output. Left-to-right shunt ratio was calculated at 40.3% from an oximetry run, under the assumption that the left anonymous vein which was not contaminated with any shunt flow could be substituted for venous return from the upper body. We could determine the indication of fistula closure according to the estimated high left-to-right shunt ratio, reducing cardiac output by 42.7% which was similar to the pre-estimated left-to-right shunt ratio. Two months later, the patient's serum B-type natriuretic peptide level and left ventricular end-diastolic and end-systolic diameters were decreased. The proposed method to estimate the left-to-right shunt ratio was useful in determining the indication for fistula closure in a patient with HF and a significant shunt fistula.
ABSTRACT
Background: Non-invasive evaluation of left ventricular (LV) diastolic dysfunction (DD) and elevated LV filling pressure are crucial for diagnosing heart failure. The 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging (ASE/EACVI) recommendations for evaluating elevated LV filling pressure (algorithm B) have acceptable diagnostic accuracy, including in patients with reduced LV ejection fraction (EF). No prior study, however, has assessed the diagnostic accuracy of algorithm A of the ASE/EACVI recommendations for evaluating LVDD in patients with normal LVEF. MethodsâandâResults: We evaluated the clinical relevance of algorithm A in 94 patients who underwent invasive LV pressure measurement. Algorithm A identified invasively defined LVDD (time constant τ≥48 ms and/or LV end-diastolic pressure ≥16 mmHg) with low sensitivity (22.4%) but high specificity (90.7%). Algorithm A also identified elevated LV filling pressure with low sensitivity (41.7%) but high specificity (87.5%), and with a high negative predictive value (90.9%). Conclusions: Algorithm A may not be useful for screening LVDD in patients with normal LVEF. Negative findings using algorithm A, however, may identify a patient with normal LVDD with high specificity, and most of such patients will have LV pre-A pressure in the normal range.
ABSTRACT
Atrial fibrillation (AF) is an exacerbating factor for exercise tolerance due to the loss of atrial kick. However, many patients with permanent AF, which lasts for at least a year without interruption, and preserved left ventricular ejection fraction (LVEF ≥ 50%) are asymptomatic and have good exercise tolerance. In such cases, the possible mechanism that compensates for the decrease in cardiac output accompanying the loss of atrial kick is a sufficient increase in heart rate (HR) during exercise. We investigated the relationship between exercise tolerance and peak HR during exercise using cardiopulmonary exercise testing in 242 male patients with preserved LVEF, 214 with sinus rhythm (SR) and 28 with permanent AF. Peak HR was significantly higher in the AF group than the SR group (148.9 ± 41.9 vs. 132.0 ± 22.0 beats/min, p = 0.001). However, oxygen uptake at peak exercise did not differ between the AF and SR groups (19.4 ± 5.7 vs. 21.6 ± 6.0 mL/kg/min, p = 0.17). In multiple regression analysis, peak HR (ß, 0.091; p < 0.001) and the interaction term constructed by peak HR and presence of permanent AF (ß, 0.05; p = 0.04) were selected as determinants for peak VO2; however, presence of permanent AF was not selected (ß, -0.38; p = 0.31). Therefore, the impact of peak HR on exercise tolerance differed between the AF and SR groups, suggesting that a sufficient increase in HR during exercise is an important factor to preserve exercise tolerance among patients with AF.
