Clinical validity of a novel doppler time interval, in assessment of left ventricular filling pressure in patients with severe mitral stenosis

Non invasive assessment of diastolic filling pressure by Doppler echocardiography is important for the interpretation of symptoms and optimization of unloading therapy in patients with severe mitral stenosis. Recently a novel Doppler time interval between the onset of early diastolic velocity mitral inflow velocity [E] and annular early diatolic velocity [Ea] by tissue Doppler imaging [T[E-Ea]], have been proposed as one of the useful indices for this assessment. Therefore, this research was intended to assess the clinical utility of this time interval [T[E-Ea], have been proposed as one of the useful indices for this assessment. Therefore, this research was intended to assess the clinical utility of this time interval [T[E-Ea] for evaluation and prediction of pulmonary capillary wedge pressure [PCWP] in patients with severe mitral stenosis. Fifty patients with severe mitral stenosis were subjected to conventional and Tissue Doppler Imaging echocardiography to estimate the time interval [T[E-Ea], and all the routine 2D, M-mode, and Doppler echocardiographic measurement were taken, simultaneously right side heart catheterization for assessment of pulmonary capillary wedge pressure was done [as can as possible] before and after balloon mitral valvuloplasty. The mean age was [26.7 +/- 5.1 years], mitral valve area range was [0.8 to 1.2Cm[2]], and before mitral valvuloplasty the estimated PCWP [by Doppler equations] was [30.8 +/- 15.3] and assessed one [by catheterization] was [30.2 +/- 14.1 for], where both values were nearly comparable. While among several Doppler measurements the strongest correlation with PCWP had been observed with Isovolumetric Relaxation Time/time constant of LV relaxation [IVRT/Tau] where [r=-0.96, p<0.001] followed by IVRT/TE-Ea [r=-0.40, p<0.001]. Also, the same previous Doppler ratios tracked well the changes in PCWP after mitral valve dilatation, and both of them were able to predict PCWP. While other Doppler parameters failed to predict it. Importantly the cutoff value to predict PCWP> 15mmHg in mitral stenosis patients, was an IVRT/T[E-Ea] <4.7 with sensitivity and specificity of 100%. Time interval [T[E-Ea] is a useful novel Doppler index for evaluation of filling pressure, since the ratios of IVRT/T[E-Ea] or IVRT to Tau were more accurate than IVRT alone when correlated to PCWP or predict it in patients with severe mitral stenosis, as well it can track changes in PCWP after mitral valvuloplasty. Clinical Implication: Such simple equation could be used for daily application and one can use the simple ratio of IVRT/T[E-Ea] to predict PCWP> 15mmHg in patients with severe mitral stenosis and that well help to decide therapeutic strategies for such patients

QRS duration in isolated left bundle branch block: a marker of ventricular remodling and septal hypoperfusion

Isolated left bundle branch block [LBBB] per se may compromise cardiac mechanics and perfusion; this may contribute to the unfavorable outcome of such patients. The relation of QRS duration in isolated LBBB with cardiac function and perfusion is unknown. So, we sought to evaluate the left ventricular [LV] function and myocardial perfusion in isolated LBBB in relation to QRS duration. The study included 30 patients with isolated LBBB and 10 age and gender matched subjects without conduction delay. All study population had normal coronary angiogram. LBBB patients were divided into group I [17 patients] with 120/=140 msec. LV end diastolic dimension [LVED], LV end systolic dimension [LVES], septal wall thickness [SWT], posterior wall thickness [PWT] and LV ejection fraction [LVEF] were detected by echocardiography and myocardial perfusion was assessed by Thallium-201 [[201]Th] scintigraphy. LV remodeling [as detected from increased LVSD and PWT and decreased LVEF] and septal hypoperfusion [as detected by 201Th scintigraphy] were more frequent in group II [patients with QRS>140 msec]. QRS as it correlated positively with LVES [r 0.79, p<0.001] and negatively with LVEF [r-0.56, p<0.002], it also showed good agreement with myocardial perfusion imaging, the prolonged QRS the more frequent septal hypoperfusion. Moreover, there was a relation between cardiac function and myocardial perfusion in LBBB patients as these patients with perfusion defects showed increased LVES and SWT and decreased LVEF versus those without perfusion defects suggesting that there is link between cardiac function and myocardial perfusion in LBBB. Electrocardiography is commonly used as the first assessment tool for possible cardiac disease. QRS duration in patients with isolated LBBB is closely related to LV remodeling and septal hypoperfusion