Inferior Mitral Annulus Research Articles

Assessment of Arterial Stiffness with Cardio-Ankle Vascular Index in Patients with Mitral Annular Calcification.

Arterial stiffness is related to arteriolosclerotic diseases and is a marker of adverse cardiovascular events. Mitral annular calcification (MAC) is progressive calcium deposition on the posterior and inferior mitral annulus and is associated with atherosclerotic cardiovascular diseases. Cardio-ankle vascular index (CAVI) is a measurement technique used to estimate the degree of arterial stiffness without effect from blood pressure. The aim of this study is to research arterial stiffness using CAVI in patients with MAC. The study was cross-sectional and observational and included 98 patients with MAC confirmed by echocardiography who referred to the cardiology clinics and met study inclusion criteria and 38 controls without MAC. CAVI measurements were obtained by using the Vascular Screening System VaSera VS-1000 (Fukuda Denshi, Tokyo, Japan) device. The two groups were similar in terms of demographic characteristics, including age, sex, hypertension, coronary artery disease, body surface area, and smoking (P > .05). Left atrial volume index was significantly higher in patients with MAC compared with the control group (P < .001). Right arm CAVI, left arm CAVI, and mean CAVI were significantly higher in the MAC group than the control group (P = .037, P = .005, and P = .014, respectively) and increased with MAC severity. There was a significant positive correlation between mean CAVI and MAC grade (r = 0.278, P = .001). Also, when ankle-brachial index (ABI) was measured with CAVI, left and right extremity ABI values were significantly lower in patients with MAC (P = .017 and P = .005, respectively). CAVI increased in all patients with MAC and associated with increasing grade of calcification.

Abnormal pattern of left atrial activation and asynchronous conduction predicted the occurrence of new atrial fibrillation: evidences for Bachmann's bundle block in atrial fibrillation pathophysiology.

Evidences suggest that recurrent atrial fibrillation (AF) is associated with left atrial (LA) remodelling. The goal of this study is to establish a method for assessment of LA remodelling and find predictors for the development of AF. This prospective study included patients without a history of AF who were evaluated using pulsed-wave tissue Doppler imaging (PW-TDI). P-wave onset to A'-wave (PA' interval) was measured at the septal, lateral, anterior, and inferior mitral annulus. Abnormal LA activation pattern was defined as an upward LA activation over the coronary sinus and delayed activation anterior. Left atrial asynchrony was measured as (i) the difference between the septal and lateral PA' interval (DLS) and (ii) the standard deviation of all four PA' intervals (SD4-PA'). The follow-up for AF recurrence (AF+) was based on symptoms and 7-day Holter electrocardiograms. Ninety-eight patients (mean age 58 ± 15 years, 47% female) were included. During a follow-up of 28 ± 9 months, AF was documented in 10%. More pronounced LA asynchrony was observed in AF+ group: DLS (AF+) 39 ± 16 vs. DLS (AF-) 20 ± 11 ms; P < 0.001, and SD4-PA' (AF+) 18.6 ± 6.4 vs. SD4-PA' (AF-) 11.7 ± 4.2 ms; P < 0.001. Abnormal LA activation was frequently observed in AF+ patients: 60% vs. 27%; P = 0.033. Electrocardiogram sign of Bachmann's bundle block (BBB) was associated with prolongation of SD4-PA': SD4-PA' (BBB+) vs. SD4-PA' (BBB-) = 18 ± 6 vs. 13 ± 4.5 ms; P = 0.007. More pronounced LA asynchrony and abnormal LA activation pattern were associated with new-onset AF.

Randomized investigation of the left atrial sweet spot for vagal denervation of atrioventricular node during the cardioneuroablation

Abstract Background Radiofrequency catheter ablation of inferior atrial ganglionic plexi frequently results in vagal denervation of the atrioventricular (AV) node. The effective sites are, however, considerably variable. Purpose We prospectively sought the left atrial (LA) ablation site with the maximum effect on AV nodal modulation. Methods The study included 16 patients (age: 46±14 years, 56% males) who underwent cardioneuroablation for recurrent reflex cardioinhibitory syncope in general anesthesia. After targeting the superior paraseptal ganglionic plexi and achieving the denervation of the sinus node, study ablations were performed at the bottom of the LA to accomplish the AV nodal denervation (Figure). Five equidistantly distributed ablation lesions (30W / 30s / 20ml/min) were created on the virtual line connecting inferior ostium of right inferior pulmonary vein (RIPV) and inferior mitral annulus (MA). Lesions were centered symmetrically relative to the posterior mid-left-atrial line. They were numbered in ascending order from #1 (more septal, closer to the RIPV) to #5 (more lateral, closer to the MA). Patients were randomly (1:1) assigned to mutually opposite direction of ablation (from site #1 to #5 or from site #5 to #1). The response of heart rhythm to extracardiac vagal nerve high-frequency stimulation (50Hz/0.05ms/1V/kg [&amp;lt;70V]/5s) were recorded at baseline and after each radiofrequency energy delivery. Results Study protocol ablations overall resulted in elimination or attenuation of inducible AV block (maximum R-R interval: 2.9±2.8 vs. 5.2±2.4s, P&amp;lt;0.001). Temporal development of effect with the progression of ablation is shown in the Figure indicating that the most lateral lesion alone produces the maximum effect. The AV nodal denervation was incomplete after per-protocol ablations in 7/16 patients. In the majority of them, the final success was achieved by extension of ablation lesion toward the inferior mitral annulus either endocardially or via the proximal coronary sinus. Conclusion Ablation of perimitral region of the inferior LA conveyed the maximum effect in terms of AV nodal denervation. Funding Acknowledgement Type of funding source: None

Catheter Ablation of Paroxysmal Atrial Fibrillation: Have We Achieved Cure with Pulmonary Vein Isolation?

Pulmonary vein isolation (PVI) is the cornerstone of current ablation techniques to eliminate atrial fibrillation (AF), with the greatest efficacy as a stand-alone procedure in patients with paroxysmal AF. Over the years, techniques for PVI have undergone a profound evolution, and current guidelines recommend PVI with confirmation of electrical isolation. Despite significant efforts, PV reconnection is still the rule in patients experiencing post-ablation arrhythmia recurrence. In recent years, use of general anesthesia with or without jet ventilation, open-irrigated ablation catheters, and steerable sheaths have been demonstrated to increase the safety and efficacy of PVI, reducing the rate of PV reconnection over follow-up. The widespread clinical availability of ablation catheters with real-time contact force information will likely further improve the effectiveness and safety of PVI. In a small but definite subset of patients, post-ablation recurrent arrhythmia is due to non-PV triggers, which should be eliminated in order to improve success. Typically, non-PV triggers cluster in specific regions such as the coronary sinus, the inferior mitral annulus, the interatrial septum, the left atrial appendage, the Eustachian ridge, the crista terminalis region, the superior vena cava, and the ligament of Marshall. Focal ablation targeting the origin of the trigger is recommended in most cases. Empirical non-PV ablation targeting the putative substrate responsible for AF maintenance with ablation lines and/or elimination of complex fractionated electrograms has not been shown to improve success compared to PVI alone. Similarly, the role of novel substrate-based ablation approaches targeting putative localized sources of AF (e.g., rotors) identified by computational mapping techniques is unclear, as they have never been compared to PVI and non-PV trigger ablation in an adequately designed randomized trial. This review highlights PVI techniques and outcomes in treating recurrent drug-refractory AF and discusses the potential role of additional non-PV ablation.

Echocardiographic Apporach to Dissect the Effect of Dyssynchrony on Left Ventricular Function in Heart Failure.

Left ventricular (LV) dyssynchrony (DYS) is believed to affect LV function. Despite extensive research, no clinically feasible method to assess the negative effect specific to DYS on the LV function has been established. To clinically evaluate this effect, we used global strain (GS) derived from color‐coded tissue Doppler imaging (TDI), as a surrogate to predict LV systolic performance and E’4, the average of peak E velocity of septal, lateral, anterior, and inferior mitral annulus as to predict early diastolic relaxation with echocardiography. We analyzed 104 consecutive patients at our laboratory from 2007 to 2009 who presented with heart failure [ages; 57±14, LVEF; 29.8±11.9%, 43 (41%) females, mean±SD]. The GS was evaluable in 61 patients (59%) and E’4 was evaluable in 83 patients (80%). GS was significantly linearly correlated with LV ejection fraction in both patients with DYS and without DYS, but these linear relationships differed statistically in these two groups by ANCOVA indicating that GS may be used to detect the specific effect of DYS on LV systolic function. On the other hand, E’4 significantly correlated with GS, LV ejection fraction, and age, but not echocardiographic measures of DYS indicating that LV early diastolic relaxation may not be affected by DYS. In conclusion, echocarciographic approach is promising to clinically evaluate the specific effect of DYS on LV function in heart failure populations.

Evaluation of left ventricular systolic function by measuring the mitral annular displacement with speckle tracking imaging

Objective To explore the value of peak systolic displacement of mitral annulus in evaluating left ventricular systolic function by speckle tracking imaging(STI).Methods The study population consisted of 96 subjects. The apical four-chamber view and two-chamber view were obtained and the systolic displacements of mitral annulus were measured at lateral, spetum, anterior and inferior mitral annulus (MADlat, MADsep, MADant, MADinf).The systolic displacements of mitral annulus midpoint (MADmid) and its ratio to the length of left ventricle at end-diastole(MADmid%) were calculated.Left ventricular ejection fraction(LVEF) was measured by three-dimensional echocardiography.The correlation of these displacements parameter with LVEF was analyzed.Results ① There was no significant difference among MADsep, MADlat, MADant, MADinf and MADmid(P>0.05).②There was significant correlation between LVEF and these parameters (P 50% was 8.9 mm with a sensitivity of 95% and a specificity of 80% while the cut off value of MADmid% for LVEF>50% was 10.9% with a sensitivity of 95% and a specificity of 85%.Conclusions Displacement of mitral annulus by STI showed an excellent correlation with LVEF, and it may be a new promising method for routine evaluation of left ventricular systolic function with its high feasibility, simplicity and accuracy. Key words: Echocardiography; Ventricular function, left; Mitral annular displacement

Correlation between BNP Levels and Doppler Echocardiographic Parameters of Left Ventricle Filling Pressure in Patients with Chagasic Cardiomyopathy

Cardiomyopathy is the most important manifestation of Chagas' disease. Brain natriuretic peptide (BNP) level and Doppler echocardiographic parameters for diastolic dysfunction have shown correlation with left ventricle (LV) filling pressures. The purpose of this study is to compare BNP levels with Doppler echocardiographic parameters in patients with chagasic cardiomyopathy. Forty-three patients (69.8% men; mean age 41.0 +/- 10.4 years) were submitted to an echocardiographic study and 39 had their BNP levels measured. BNP levels increased with the deterioration of the diastolic function (P=0.025). Pulmonary venous flow parameters were correlated with BNP levels, but E/E'ratio (E'measured at the inferior mitral annulus) was the only diastolic parameter that remained an independent predictor of elevated BNP levels in the multivariate analysis. The area under the receiver-operating curve for BNP to detect E/E' >15 was 0.875. A BNP value of 280.4 pg/ml had a sensitivity of 96% and a specificity of 75% for predicting E/E' >15. In a group of patients with chagasic cardiomyopathy, BNP levels correlated with diastolic function patterns regardless of systolic function. The E/E'ratio (inferior wall) was the only isolated parameter of diastolic function that was independently associated with BNP levels.

Echocardiographic predictors of functional capacity in endomyocardial fibrosis patients

Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy manifested mainly by diastolic heart failure. It is recognized that diastole is an important determinant of exercise capacity. The purpose of this study was to determine whether resting echocardiographic parameters might predict oxygen consumption (VO(2p)) by ergoespirometry and the prognostic role of functional capacity in EMF patients. A total of 32 patients with biventricular EMF (29 women, 55.3 +/- 11.4 years) were studied by echocardiography and ergoespirometry. The relationship between the echocardiographic indexes and the percentage of predicted VO(2p) (%VO(2p)) was investigated by the 'stepwise' linear regression analysis. The median VO(2p) was 11 +/- 3 mL/kg/min and the %VO(2p) was 53 +/- 9%. There was a correlation of %VO(2p) with an average of A' at four sites of the mitral annulus (A' peak, r = 0.471, P = 0.023), E'/A' of the inferior mitral annulus (r = -0.433, P = 0.044), and myocardial performance index (r = -0.352, P = 0.048). On multiple regression analysis, only A' peak was an independent predictor of %VO(2p) (%VO(2p)= 26.34 + 332.44 x A' peak). EMF patients with %VO(2p)< 53% had an increased mortality rate with a relative risk of 8.47. In EMF patients, diastolic function plays an important role in determining the limitations to exercise and %VO(2p) has a prognostic value.

Pulmonary vein antrum isolation

Pulmonary vein antrum isolation offers safe and effective treatment of atrial fibrillation by eliminating the potential triggers of this arrhythmia. The pulmonary vein antra encompass, in addition to the pulmonary veins, the left atrial roof and posterior wall and, in the case of the right pulmonary vein antra, a portion of the interatrial septum. Compared with pulmonary vein ostial isolation, this technique offers a higher success rate and a lower complication rate. In patients with nonparoxysmal atrial fibrillation, extension of septal ablation to the region of the mitral annulus is associated with better outcomes. Further adjunctive strategies include ablation in the coronary sinus, atrial side of inferior mitral annulus, superior vena cava, and along the cristae terminalis, targeting complex fragmented electrograms. We usually reserve these adjunctive ablative therapies for patients with persistent or chronic atrial fibrillation and those with unsuccessful prior catheter ablation.