Assessment of subclinical left ventricular dysfunction in patients with chronic mitral regurgitation using torsional parameters described by tissue Doppler imaging.

BACKGROUND: Left ventricular (LV) twist is due to oppositely directed apical and basal rotation and has been proposed as a sensitive marker of LV function. We sought to assess the impact of chronic pure mitral regurgitation (MR) on the torsional mechanics of the left human ventricle using tissue Doppler imaging. METHODS: Nineteen severe MR patients with a normal LV ejection fraction and 16 non-MR controls underwent conventional echocardiography and apical and basal short-axis color Doppler myocardial imaging (CDMI). LV rotation at the apical and basal short-axis levels was calculated from the averaged tangential velocities of the septal and lateral regions, corrected for the LV radius over time. LV twist was defined as the difference in LV rotation between the two levels, and the LV twist and twisting/untwisting rate profiles were analyzed throughout the cardiac cycle. RESULTS: LV twist and LV torsion were significantly lower in the MR group than in the non-MR group (10.38° ± 4.04° vs. 13.95° ± 4.27°; p value = 0.020; and 1.29 ± 0.54 °/cm vs. 1.76 ± 0.56 °/cm; p value = 0.021, respectively), both suggesting incipient LV dysfunction in the MR group. Similarly, the untwisting rate was lower in the MR group (-79.74 ± 35.97 °/s vs.-110.96 ± 34.65 °/s; p value = 0.020), but there was statistically no significant difference in the LV twist rate. CONCLUSION: The evaluation of LV torsional parameters in MR patients with a normal LV ejection fraction suggests the potential role of these sensitive variables in assessing the early signs of ventricular dysfunction in asymptomatic patients.

Premeasured neochordae loop maker: a new technology in mitral valve repair.

The exact length of neochordae loops plays the major role in the success of mitral valve repair. The Neochordae Loop Maker is a novel device that models the left ventricular structure in an individual patient. Preoperative transthoracic echocardiography is used to identify the geometry of each papillary muscle and set up the device for the patient. All required neochordae loops are made in the operating room before initiating the cardiopulmonary bypass. In the calibration phase, seven consecutive patients who were candidates for mitral valve replacement underwent transthoracic echocardiography. The device was set up for each patient, and the length of their normal chordae and their respective neochordae was compared by the Bland-Altman analysis. From seven excised mitral valves, 21 chordae were considered normal (gold standard). The length of these gold standards (1.92 ± 0.67 cm) and their respective neochordae (1.93 ± 0.69 cm) showed agreement by the Bland-Altman analysis. The proposed technology showed satisfactory preliminary results in creating the premeasured neochorda loops inasmuch as it reduced the complexity of minimally invasive surgeries.

Neochordameter: a new technology in mitral valve repair.

BACKGROUND: Mitral valve repair has shown superior results compared to mitral valve replacement in patients with mitral valve prolapse. Using premeasured neochordae (the loop technique) has been proposed for both anterior and posterior leaflet repairs. However, there are two major problems that are usually experienced using this method. One is deciding the length of the neo-chordae, and the other is tying the knot at the intended length. OBJECTIVES: This study introduced a new technology in mitral valve repair that reduces the complexity of making neo-chordae loops, especially in minimally invasive surgeries. PATIENTS AND METHODS: Neochordameter is a new device which utilizes preoperative transthoracic echocardiography to determine the exact length of required neochordae and enable surgeons to make neochordae loops before starting the cardiopulmonary bypass. In this study, we applied this technique in mitral valve repair of three patients. RESULTS: Two of these patients were male and the other one was female. All of them had severe mitral regurgitation requiring anterior leaflet repair. Total eight neochordae loops were used in these patients. No change in the length of neochordae was required after saline test and all of these patients had none or trivial mitral regurgitation by intraoperative and follow up transesophageal echocardiography. No complication was seen in six-month follow up. CONCLUSIONS: The ability of this technology in developing premeasured neo-chordae loops with accurate sizes and not needing the post-implantation length adjustment which is efficient in reducing the complexity of both minimally invasive and conventional surgeries are the issues which is going to be regarded .

Giant aneurysmal fistula of the left main coronary artery to the right atrium.

A 42-year-old woman presented to our outpatient department with complaints of atypical chest pain and palpitation. On physical examination, the patient's blood pressure was 140/95 mm Hg, and there was a systolic cardiac murmur on the left sternal border. A transthoracic echocardiography examination was performed, and a left-to-right shunt ratio (Qp/Qs) of approximately 1.5 was detected. Computed tomography angiography and coronary angiography examinations confirmed the presence of a large fistula between the left main coronary artery and the right atrium, with giant aneurysm formation and an intact right coronary artery. Surgical closure of the shunt was performed with a good final result.

Doppler echocardiographic assessment of pulmonary prostheses: a comprehensive assessment including velocity time integral ratio and prosthesis effective orifice area.

OBJECTIVE: Few reports have been published on the Doppler-derived echocardiographic data for pulmonary valve prostheses (PVPs). The aim of this study was to provide a comprehensive Doppler echocardiographic assessment of PVPs. METHODS: We studied 40 patients (mean age 24.2) with PVPs: 13 (32.5%) mechanical and 27 (67.5%) bioprosthetic valves. After clinical evaluation, all patients underwent complete, two-dimensional and Doppler studies. RESULTS: In 30 patients with normally functioning PVPs, the mean (SD) peak velocity was 2.33 (0.36) m/s with an average peak pressure gradient of 22.69 (6.7) mm Hg and an average mean pressure gradient of 12.5 (4.1) mm Hg. The mean PVPs velocity time integral (VTI) was 47.49 (12.78) cm with mean right ventricle outflow tract/peak velocity (PV) VTI ratio 0.43 (0.14), mean PVPs effective orifice area was 1.63 (0.36) cm(2). Metallic PVPs had significantly better hemodynamic Doppler study compared with biologic PVPs. In 9 patients with PVP malfunction, average peak PVPs velocity, average peak pressure gradient, mean pressure gradient, PV VTI, PV/left ventricle outflow tract VTI ratio was significantly increased (P < 0.05). CONCLUSION: This study contributes to establishing the normal range for Doppler hemodynamics in various PVPs.

Echocardiographic evaluation of mitral geometry in functional mitral regurgitation.

OBJECTIVES: We sought to evaluate the geometric changes of the mitral leaflets, local and global LV remodeling in patients with left ventricular dysfunction and varying degrees of Functional mitral regurgitation (FMR). BACKGROUND: Functional mitral regurgitation (FMR) occurs as a consequence of systolic left ventricular (LV) dysfunction caused by ischemic or nonischemic cardiomyopathy. Mitral valve repair in ischemic MR is one of the most controversial topic in surgery and proper repairing requires an understanding of its mechanisms, as the exact mechanism of FMR are not well defined. METHODS: 136 consecutive patients mean age of 55 with systolic LV dysfunction and FMR underwent complete echocardiography and after assessing MR severity, LV volumes, Ejection Fraction, LV sphericity index, C-Septal distance, Mitral valve annulus, Interpapillary distance, Tenting distance and Tenting area were obtained. RESULTS: There was significant association between MR severity and echocardiogarphic indices (all p values < 0.001). Severe MR occurred more frequently in dilated cardiomyopathy (DCM) patients compared to ischemic patients, (p < 0.001). Based on the model, only Mitral valve tenting distance (TnD) (OR = 22.11, CI 95%: 14.18 - 36.86, p < 0.001) and Interpapillary muscle distance (IPMD), (OR = 6.53, CI 95%: 2.10 - 10.23, p = 0.001) had significant associations with MR severity.Mitral annular dimensions and area, C-septal distance and sphericity index, although greater in patients with severe regurgitation, did not significantly contribute to FMR severity. CONCLUSION: Degree of LV enlargement and dysfunction were not primary determinants of FMR severity, therefore local LV remodeling and mitral valve apparatus deformation are the strongest predictors of functional MR severity.

Prevalence of mechanical dyssynchrony in heart failure patients with different QRS durations.

BACKGROUND: Cardiac resynchronization therapy (CRT) has emerged as an established therapy for congestive heart failure. However, up to 30% of patients fail to respond to CRT despite prolonged QRS. OBJECTIVES: This study aimed at defining the prevalence of interventricular and intraventricular dyssynchrony in heart failure patients with different QRS durations. METHODS: A total of 123 consecutive patients with severe heart failure (LVEF < 35% and NYHA class III-IV) were prospectively evaluated using 12-lead electrocardiogram and complete echocardiographic examination including tissue Doppler imaging. RESULTS: According to the QRS duration, 56 patients had a QRS duration < or = 120 ms (Group 1), 33 patients had a QRS duration between 120 and 150 ms (Group 2), and 34 patients had a QRS duration > or = 150 ms (Group 3). Intraventricular dyssynchrony was present in 36% of Group 1 patients, in 58% of Group 2 patients, and in 79% of Group 3 patients (P < 0.000). Linear regression demonstrated a weak relation between QRS and intraventricular dyssynchrony. A greater proportion of patients with interventricular dyssynchrony was observed in Group 3 or Group 2 compared to patients with normal QRS duration (32% in Group 1 vs. 51.5% in Group 2 vs. 76.5% in Group 3, P < 0.000). Linear regression demonstrated a significant relation between QRS duration and interventricular mechanical delay. CONCLUSIONS: Although both interventricular and intraventricular dyssynchrony increased with the increasing QRS duration, the correlation between intraventricular mechanical and electrical dyssynchrony was weak. The lack of intraventricular dyssynchrony in a fraction of patients with standard CRT indication by QRS duration may provide us insight into the nonresponders rates.

Aorta-to-left ventricle tunnel associated with noncompaction left ventricle.

We present a case of aorta-to-left ventricle (LV) tunnel and noncompaction LV in a 26-year-old woman. She was referred to our echocardiography laboratory for evaluation of aortic regurgitation by echocardiographic examination, which led to the diagnosis of the congenital abnormality of aorta-to-LV tunnel and noncompaction LV.