Effect of renal sympathetic denervation used in the treatment of resistant arterial hypertension on left ventricular hypertrophy and diastolic function

Background: Hypertension [HTN] results in structural and functional cardiac changes which increase cardiovascular morbidity and mortality. The effect of renal denervation [RD] on left ventricular hypertrophy [LVH] and left ventricular [LV] diastolic function is still unclear

Objective: This study investigated the effect of catheter-based renal sympathetic denervation on LVH and diastolic function in patients with resistant hypertension

Methods: We evaluated systolic and diastolic blood pressure [SBP and DBP, LV size, mass and diastolic function before and 6 months after RD in 68 patients with resistant hypertension by transthoracic echocardiography and Doppler

Results: SBP and DBP reduced 6 months after RD [-22 +/- 3 mmHg and -10 +/- 12mmHg; P<0.0001 respectively] LV mass index decreased similarly independent on BP response [-19.37 +/- 2.6 gm/m[2]: P<0.0001]. Diastolic parameters E/A ratio, E-wave deceleration time and intra-ventricular relaxation time improved similarly in all patients after 6 months [0.89 +/- 0.04; P=0.001, -24.85 +/- 8.93 ms; P=0.007 and -6.97 +/- 2.57 ms; P=0.012 respectively]

Conclusion: In patients with resistant hypertension and beside blood pressure lowering effect, renal denervation improves left ventricular hypertrophy and diastolic function. The relation of BP reduction effect and the improvement of cardiac hypertrophy and systolic function suggests a direct effect of sympathetic activity on LV remodeling and function which needs to be confirmed in larger prospective cohorts

RVoutflow tract pacing versus RV Apical pathophysiologic Effects and prognostic implications

Right ventricular apical pacing has been reported to be associated with adverse haemodynamic effects and alternative sites of pacing have been recommended. On the other hand RV septal pacing was claimed to be more physiological. The present work is intended to compare the classic right ventricular apical DDD pacing to RV outflow tract [RVOT] pacing in both normal and diseased hearts. We studied 30 patients [pts] with complete heart block [CHB]. Fourteen pts [Group I] had no underlying heart disease [8M and 6F with mean age 64.1 +/- 6.4, range 54-76 years] and 16 [Group II] had heart disease [10M, 6F, with mean age 67.5 +/- 8.9, range 58-86 years] including DCM in 12, 1HD in 3 and RHD in Ipt. Right ventricular apical pacing was conducted in 7pts from group I and 8pts from group II. RVA was conducted in 7pts of group I and 8pts of group II. Besides clinical evaluation, all pts were subjected to 2D echo before, and 6 months after pacing. Echo parameters studied included LVEDD, LVESD, EF% and CO with effects expressed in terms of% changes in various parameters. Compared to RVA pacing RVOT pacing in group I [pts with normal heart] induced insignificant% decrease in LVEDD [2.4 +/- 4.8vs 8.6 +/- 9.3, p value =0.146] or LVESD [4.6 +/- 7.8vs 8.3 +/- 6.0,p value =0.113] and insignificant increase in EF [2.4 +/- 4.6vs 0.42.6, p value =0.113] and CO [2.8 +/- 8.0vs 3.3 +/- 3.5, p value =0.08]. However in RVOT pacing in group II [pts with disease heart] induced significantly greater% decrease in LVEDD [3.0 +/- 2.8vs 1.2 +/- 2.3, p=0.005] in LVESD [3.7 +/- 0.9vs 2.5 +/- 2.3, p=0.000], and significantly greater% increase in EF [8.9 +/- 3.3vs I.7 +/- 1.2,p=0.001] and CO [5.8 +/- 9.6vs 10.7 +/- 18.3, p=0.04] in comparison to RVA pacing in group II In the presence of underlying cardiac dysfunction, DDD pacing by RVOT lead is hemodynamically more advantageous to classic RV apical pacing in terms of improving dimensions and enhancing systolic function. We recommend RVOT pacing in the presence of underlying HD to avoid the so called pacing-induced cardiomyopathy.