Correlational Study Of Left Ventricular Pacing Sites And Clinical Outcome Of Cardiac Resynchronization Therapy

ObjectiveTo analyze the correlation between left ventricular pacing sites and the clinical outcome of CRT in patients with chronic heart failure. To determine whether the left ventricular pacing sites will affect the responsiveness of CRT and whether the optimal left ventricular lead positions will bring the best clinical effects.Methods204patients who received CRT-P/D in Department of Cardiology in Second Affiliated Hospital School of Medicine Zhejiang University (141male,63female,64.8±11.9years, follow-up of17.8±14.9months) were included in this clinical study. The left ventricular pacing sites of all cases were grouped in three different methods as the short axis, long axis of the left ventricular and whether the pacing site is optimal:1.In the left anterior oblique view or short-axis view of the left ventricle, it was divided into three groups as anterior, lateral (including anteriolateral, lateral and posteriolateral area) and posterior wall;2. In the right anterior oblique view or long-axis view of the left ventricle, it was divided into three groups as apical, middle and basal segment of the left ventricle;3. According to whether the pacing site is the optimal pacing site (refers to left ventricular pacing sites located in the lateral wall in the view of LAO450and basal or middle segments in the view of RAO300), it was divided into two groups as optimal site group and non-optimal site group. Analyze the clinical data collected before and after procedure. The primary endpoint was defined as cardiac death or heart failure hospitalization three months after CRT, the secondary endpoint was the improvement of NYHA class and LVEF、LVEDD、LVESD. Survival estimates were calculated by the Kaplan-Meier method and a log-rank test was used to compare survival between groups.ResultsGroups divided by ventricular short axis had no significant differences in improvement of NYHA (P=0.754), LVEF (P=0.966) and LVEDD (P=0.349). Groups divided by ventricular long-axis had no significant differences in NYHA (P=0.07), LVEF (P=0.997), LVEDD (P=0.688). The optimal site group had no significant improvement in NYHA (P=0.13), LVEF (P=0.928), LVEDD (P=0.123) compared to non-optimal site group. Correlation analysis of primary endpoint events showed that there was no significant difference in cardiac death and heart failure hospitalization among groups of anterior, lateral and posterior wall (P=0.98), the cardiac death and heart failure hospitalization after CRT in apical patients was higher than that in non-apical patients (P=0.03), there was no significant difference in mortality or readmission rate between the optimal site group and non-optimal site group (P=0.11).ConclusionsLeft ventricular pacing brings clinical benefits regardless of the pacing site. There is no significant difference of clinical benefits in groups with different pacing sites (anterior, lateral or posterior wall, apical or non-apical, optimal pacing site or non-optimal pacing site). However, left ventricular leads positioned in apical region are associated with an unfavorable outcome. It should be avoided to place the left ventricular lead in the apical region. PART TWO The application of multidetector computed tomography coronary venous angiography examination in patients with heart failure underwent cardiac resychronization therapyObjectiveThis study was designed to evaluate the value of multidetector computed tomography (MDCT) coronary venous angiography examination befor cardiac resychronization therapy (CRT).MethodsThe MDCT scans of35patients (25men, age65.2±12.1years) with a history of chronic heart failure were studied. The interindividual variability int terms of diameter, distance, angle of the maintributaries of the coronary venous system was analyzed. Retrograde coronary venography was performed during the procedure.ResultThe coronary sinus (CS), great cardiac vein (GCV), middle cardiac vein (MCV) were observed in all patients. Both the posterior vein of the left ventricular (PVLV) and the left marginal vein (LMV) were present in26(74.28%) patients. The mean length of CS was47.29±8.13mm, the diameter of the CS ostium was12.50±4.97mm and10.99±3.35mm respectively in supero-inferior and antero-posterior directions. the mean diameter of MCV/PVLV/LMV was6.13±1.57mm/5.03±1.89mm/4.9±1.64mm respectively, the angle between MCV/PVLV/LMV and CS form right atrum side was65.11±16.690/117.73±34.380/114.23±47.560respectively, the distance between MCV/PVLV/LMV and CS ostium was12.0±6.04mm/34.15±13.42mm/62.51±19.82mm. The LMV was chosen in28(80%) patients for left ventricular (LV) lead, and6(17.14) PVLV were chosen.ConclusionThe anantomy of the CS and its tributaries can be evaluated by MDCT. The pre-implantation knowledge of the venous anatomy may help to guide the LV lead placement.