bstructive sleep apnea (OSA) is common, underdiagnosed and associated with cardiovascular diseases such as heart failure, left ventricular (LV) and right ventricular (RV) dysfunction, myocardial infarction, arrhythmias, and systemic and pulmonary hypertension. 1 Previous studies have shown the adverse affects of OSA on both LV and RV functions. 2,3 However, many risk factors for OSA, such as excess weight, male sex and advanced age, are the same as the risk factors for cardiovascular diseases. Proving that OSA actually causes cardiac dysfunction independent of these confounding risk factors is difficult. Early recognition of RV dysfunction before pulmonary arterial (PA) hypertension develops is important for preventing further progression to heart failure and even death. 4 Thus, there is a need for a more detailed analysis of its pathophysiologic importance and for techniques that may supplement available technology in identifying early signs of RV impairment.
Editorial p 250Recently, tissue Doppler imaging (TDI) and strain/strain rate (SR) imaging have been shown to be reliable and accurate novel techniques for evaluating global and regional ventricular function. 5 As TDI has the disadvantage of being preload and afterload dependent, a new TDI-derived index of isovolumic myocardial acceleration (IVA) has been validated to be a reliable and relatively load independent measure of cardiac systolic function. 6 Velocity vector imaging (VVI) is a novel method based on 2-dimensional B-mode images. The method involves tracking ultrasonic speckles permitting angle-independent measurement of tissue velocity and deformation. 7 It has been shown to be a reliable method for the quantification of regional contractile dysfunction with the ability to detect subclinical cardiac dysfunction. 8 In this study, VVI and TDI were used to evaluate regional subclinical RV dysfunction in newly diagnosed moderate-to-severe OSA The aims of this study were to evaluate subclinical regional right ventricular (RV) dysfunction in newly diagnosed obstructive sleep apnea (OSA) patients without systemic and pulmonary arterial (PA) hypertension, and to correlate OSA severity to RV dysfunction, using both velocity vector imaging (VVI)-derived strain imaging and tissue Doppler imaging (TDI).
Saline irrigated radiofrequency modified maze procedure was performed safely and efficiently. Both the left and bi-atrial procedures were successful in terms of restoring sinus rhythm. Our current policy is to adopt the bi-atrial approach in patients with a history of atrial flutter and where the right atrium has to be opened. Otherwise the procedure is restricted to the left atrial side.
Background:The aim of the present study was to evaluate pre-existent subclinical mechanical atrial dysfunction in patients with postoperative atrial fibrillation (POAF) by using novel echocardiographic techniques.
Methods and Results:Ninety-six patients with sinus rhythm, undergoing coronary artery bypass graft (CABG) operation were prospectively enrolled. Preoperative left atrial (LA) reservoir, conduit and booster functions were evaluated by 3 different methods: conventional echocardiography, tissue Doppler imaging (TDI), and 2-dimensional strain imaging based-velocity vector imaging (VVI). POAF occurred in 25 out of 96 patients (26%). LA volume index (LAVI) was the only conventional parameter associated with POAF. TDI-derived LA velocities were similar in study groups. In VVI analysis, LA systolic strain, strain rate (SRs) and early diastolic strain rate (ESRd) were impaired in patients who developed POAF after CABG (P=0.0001). Age, LAVI, LA peak systolic strain, SRs and ESRd were found to be the independent predictors of POAF. The optimal cut-off point of 44.0% (88.7% sensitivity, 96% specificity) for LA strain, 1.7 s -1 (88% sensitivity, 86.2% specificity) for SRs and 1.95 s -1 (sensitivity 72%, 70.4% specificity) for ESRd predicted POAF in this study.Conclusions: VVI-derived strain imaging could be used as an adjunctive non-invasive method for evaluating subclinical atrial mechanical dysfunction in patients undergoing CABG. This might help us to identify patients with high risk of POAF in clinical practice. (Circ J 2010; 74: 2109 - 2117
We detected significantly decreased FMD and increased CIMT in TAK, suggesting a marked endothelial dysfunction. Both chronic systemic inflammation and vasculitis might lead to endothelial dysfunction and increased atherosclerosis in TAK, suggesting that management of cardiovascular risk factors are also important in the management of vasculitis.
Objectives: We investigated right ventricular (RV) structural and functional cardiac alterations in obstructive sleep apnea (OSA) independent of systemic hypertension and their correlation to the severity of OSA. Methods: Forty-one moderate-to-severe OSA but otherwise healthy patients and 30 body mass index-matched control subjects were included. All subjects underwent 24-hour ambulatory blood pressure monitoring, standard and tissue Doppler imaging of the RV. Results: The OSA group had increased RV wall thickness, impaired right ventricular outflow tract fractional shortening (RVOT fs), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI) and RV myocardial acceleration during isovolumic contraction (IVA) (p < 0.001). Apnea hypopnea index (AHI) and mean pulmonary artery (PA) pressure were correlated with all these indices (p < 0.01 for all). RV free wall thickness (p < 0.001) and IVA (p = 0.006) remained significant predictors of AHI after adjusting for age, body mass index, mean PA pressure, RVOT fs, TAPSE and MPI in a multiple stepwise linear regression model. Conclusions: OSA is associated with impaired RV function despite normal systemic blood pressures. The level of RV dysfunction has a direct relationship with the severity of OSA. RV free wall thickness and IVA are independent predictors of AHI in uncomplicated OSA patients.
VVI- derived strain imaging and TDI-derived IVA may be used as adjunctive, reliable, noninvasive parameters for evaluating subclinical ventricular dysfunction in patients with chronic, severe AR. This may help to identify patients for closer follow-up and to determine the need for surgery before developing irreversible, severe heart failure.
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