Study of immediate and late effects of successful PTMC on left atrial appendage function in patients with severe rheumatic mitral stenosis IN SINUS rhythm.

INTRODUCTION: Since its introduction in 1984, Percutaneous Transvenous Mitral Commissurotomy (PTMC) has become established as a safe and effective treatment for rheumatic Mitral Stenosis (MS).( Ben Farhat et al., 1998) 1 Chronic pressure and volume overload imposed by MS causes left atrial (LA) and Left Atrial Appendage (LAA) dysfunction. Risk of cerebrovascular accident (CVA) is increased approximately 17-fold in patients of MS in Atrial Fibrillation (AF) and is present even in patients of MS in sinus rhythm (SR). This study was undertaken to evaluate the effect of PTMC on LAA function by Trans-esophageal echocardiography (TEE) Doppler and Doppler Tissue Imaging (DTI). METHODS: Total 70 cases were enrolled in this study. Patients with symptomatic severe MS (Mitral Valve Area <1.5cm2), in SR, who underwent a successful PTMC during the period from May 2016 to May 2019 were selected. All the patients underwent Clinical examination, ECG, detailed TTE and TEE before, immediately after (within 24 h) & after 6 months of PTMC. RESULTS: There was non significant improvement in Left Atrial appendage fractional area change {LAAAC (%)} immediately Post PTMC but there was significant improvement at 6 months Post PTMC. There was significant increase in LAA PW Doppler velocities (LAAEDE, LAALDE and LAAF velocity) immediately Post PTMC which got further improved significantly at 6 months of follow up. There was significant increase in LAA DTI velocities (ELAA, ALAA and SLAA velocity) immediately Post PTMC which got further improved significantly at 6 months of follow up. CONCLUSION: PTMC improves left atrial appendage function in patients with mitral stenosis.

Arterial-ventricular and interventricular interaction in isolated post-capillary and combined pulmonary hypertension in severe mitral stenosis.

BACKGROUND: Isolated post-capillary pulmonary hypertension (Ipc-PH) is characterized by elevated left atrial pressures that are passively transmitted upstream, whereas combined pre- and post-capillary PH (Cpc-PH) demonstrates additional reactive changes in pulmonary vasculature. The increased load imposed on the right ventricle (RV) influences left ventricular (LV) mechanics by means of interventricular interaction. However, there is lack of evidence to substantiate the effect of possible additional alterations in the arterio-ventricular (AV) coupling and their effect on LV function. Considering the discrepant RV load in Cpc-PH and Ipc-PH, we sought to investigate whether these two conditions are also characterized by differential alterations in AV coupling. METHODS AND RESULTS: Invasive hemodynamic and echocardiographic data of 120 patients with PH due to severe rheumatic mitral stenosis before and immediately after percutaneous valvulotomy, along with 40 age-matched healthy controls, were analyzed. Effective arterial (E a) and ventricular elastance (E es) were measured. PH patients demonstrated elevated LV afterload (E a) along with AV uncoupling, and these derangements were more evident in the Cpc-PH group [E a: 3.3 (2.3-5.4) vs 2.6 (2.1-3.5) mmHg/mL, E a/E es: 0.73 (0.6-0.9) vs 0.88 (0.7-1.2), p < 0.05]. In addition, PH was associated with reduced LV deformation, which was mainly determined by elevated E a, while the effect of interventricular interaction was limited to the septal wall. CONCLUSIONS: Our results suggest that in addition to the interventricular interaction, an abnormal AV coupling contributes to the altered LV mechanics that has been associated with adverse prognosis in Cpc-PH.

The impact of arterial load on left ventricular performance: an invasive haemodynamic study in severe mitral stenosis.

KEY POINTS: A hallmark of mitral stenosis (MS) is the markedly altered left ventricular (LV) loading. As most of the methods used to determine LV performance in MS patients are influenced by loading conditions, previous studies have shown conflicting results. The present study calculated LV elastance, which is a robust method to quantify LV function. We demonstrate that LV loading in MS patients is elevated but normalizes after valve repair and might be a result of reflex pathways. Additionally, we show that the LV in MS is less compliant than normal due to a combination of right ventricular loading and the valvular disease itself. Immediately after valve dilatation the increase in blood inflow into the LV results in even greater LV stiffness. Our findings enrich our understanding of heart function in MS patients and provide a simple reproducible way of assessing LV performance in MS. ABSTRACT: Left ventricular (LV) function in rheumatic mitral stenosis (MS) remains an issue of controversy, due to load dependency of previously employed assessment methods. We investigated LV performance in MS employing relatively load-independent indices robust to the altered loading state. We studied 106 subjects (32 ± 8 years, 72% female) with severe MS (0.8 ± 0.2 cm(2) ) and 40 age-matched controls. MS subjects underwent simultaneous bi-ventricular catheterization and transthoracic echocardiography (TTE) before and immediately after percutaneous transvenous mitral commisurotomy (PTMC). Sphygmomanometric brachial artery pressures and TTE recordings were simultaneously acquired in controls. Single-beat LV elastance (Ees ) was employed for LV contractility measurements. Effective arterial elastance (Ea ) and LV diastolic stiffness were measured. MS patients demonstrated significantly elevated afterload (Ea : 3.0 ± 1.3 vs. 1.5 ± 0.3 mmHg ml(-1) ; P < 0.001) and LV contractility (Ees : 4.1 ± 1.6 vs. 2.4 ± 0.5 mmHg ml(-1) ; P < 0.001) as compared to controls, with higher Ea in subjects with smaller mitral valve area (≤ 0.8 cm(2) ) and pronounced subvalvular fusion. Stroke volume (49 ± 16 to 57 ± 17 ml; P < 0.001) and indexed LV end-diastolic volume (LVEDVindex : 57 ± 16 to 64 ± 16 ml m(-2) ; P < 0.001) increased following PTMC while Ees and Ea returned to more normal levels. Elevated LV stiffness was demonstrated at baseline and increased further following PTMC. Our findings provide evidence of elevated LV contractility, increased arterial load and increased diastolic stiffness in severe MS. Following PTMC, both LV contractility and afterload tend to normalize.

The pulmonary capillary wedge pressure accurately reflects both normal and elevated left atrial pressure.

BACKGROUND: Pulmonary capillary wedge pressure (PCWP) is routinely used as an indirect measure of the left atrial pressure (LAP), although the accuracy of this estimate, especially under pathological hemodynamic conditions, remains controversial. OBJECTIVES: The aim of this prospective study was to investigate the reliability of PCWP for the evaluation of LAP under different hemodynamic conditions. METHODS: Simultaneous left and right heart catheterization data of 117 patients with pure mitral stenosis, obtained before and immediately after percutaneous mitral comissurotomy, were analyzed. RESULTS: A strong correlation and agreement between PCWP and LAP measurements was demonstrated (correlation coefficient = 0.97, mean bias ± CI, 0.3 ± -3.7 to 4.2 mm Hg). Comparison of measurements performed within a 5-minute interval and those performed simultaneously revealed that simultaneous pressure acquisition yielded better agreement between the 2 methods (bias ± CI, 1.82 ± 1.98 mm Hg). In contrast to previous observations, the discrepancy between the 2 measures did not increase with elevated PCWP. Multiple regression analysis failed to identify hemodynamic confounders of the discrepancy between the 2 pressures. The ability of PCWP to distinguish between normal and elevated LAP (cutoff set at 12 and 15 mm Hg, respectively), as tested by receiver operating characteristics analysis, demonstrated a remarkably high diagnostic accuracy (area under the curve: 0.989 and 0.996, respectively). CONCLUSIONS: Although the described limits of agreement may not allow the interchangeability of PCWP and LAP, especially at lower pressure ranges, our data support the clinical use of PCWP as a robust and accurate estimate of LAP.