Assessment of Mitochondrial Dysfunction and Monoamine Oxidase Contribution to Oxidative Stress in Human Diabetic Hearts.

Mitochondria-related oxidative stress is a pathomechanism causally linked to coronary heart disease (CHD) and diabetes mellitus (DM). Recently, mitochondrial monoamine oxidases (MAOs) have emerged as novel sources of oxidative stress in the cardiovascular system and experimental diabetes. The present study was purported to assess the mitochondrial impairment and the contribution of MAOs-related oxidative stress to the cardiovascular dysfunction in coronary patients with/without DM. Right atrial appendages were obtained from 75 patients randomized into 3 groups: (1) Control (CTRL), valvular patients without CHD; (2) CHD, patients with confirmed CHD; and (3) CHD-DM, patients with CHD and DM. Mitochondrial respiration was measured by high-resolution respirometry and MAOs expression was evaluated by RT-PCR and immunohistochemistry. Hydrogen peroxide (H2O2) emission was assessed by confocal microscopy and spectrophotometrically. The impairment of mitochondrial respiration was substrate-independent in CHD-DM group. MAOs expression was comparable among the groups, with the predominance of MAO-B isoform but no significant differences regarding oxidative stress were detected by either method. Incubation of atrial samples with MAOs inhibitors significantly reduced the H2O2 in all groups. In conclusion, abnormal mitochondrial respiration occurs in CHD and is more severe in DM and MAOs contribute to oxidative stress in human diseased hearts with/without DM.

Pre-operative transthoracic real-time three-dimensional echocardiography for a better surgical strategy.

UNLABELLED: In this study we aimed to evaluate the three-dimensional (3D) transthoracic echocardiography (TTE) in the assessment of cardiac valve morphology. METHODS: Bidimensional (2D) and real-time 3D TTE was performed in 104 patients consecutive with cardiac catheterisation, prior to valve surgery. Using surgical findings as the gold standard, 2D and 3D TTE were compared for adequate recognition and accurate detection of morphology. A scoring protocol was used for recognition of the valvular segments (0= inadequate, 1 = adequate). RESULTS: Adequate echographic visualization of the valve segments was more frequently obtained by 3D than 2D TTE imaging (731/770 by 3D TTE vs. 693/770 by 2D TTE, p < 0.01). The valve leaflets segments were more clearly identified by 3D TTE rather than by 2D TTE (502/531 vs. 471/531, p <0.01). The assessment of commissures was similar by both methods (229/239 vs. 222/239, p=0.09). Total 3D TTE scores for mitral and aortic valves were significantly better than 2D ITE scores (mean score 12.91+/-1.62 by 3D vs 11.58+/-1.02 by 2D, p=0.02). This superiority of 3D TTE was irrespective of rhythm (p <0.05 for both sinus rhythm and atrial fibrillation). Using surgical classification of valvular disease as gold standard, the sensibility and specificity were 91% and 84 % for 3D TTE, and 85% and 77% for 2D TTE, respectively. CONCLUSIONS: Real-time 3D was superior to 2D TTE forthe accurate localization and identification of valvular pathology, irrespective of heart rhythm.

The influence of left bundle branch-block and cardiac dyssynchrony on 2D-strain parameters in patients with heart failure complicating ischemic cardiomyopathy.

UNLABELLED: Coronary artery disease is the underlying cause in approximately two-thirds of patients with heart failure. Torsional and longitudinal deformations are essential components of left ventricular (LV) performance. Electric conduction defects can reduce LV ejection fraction (LVEF) and decrease cardiac output. AIM: To investigate the influence of left bundle branch-block (LBBB) and cardiac dyssynchrony on 2D-strain parameters in patients with HF complicating ischemic cardiomyopathy. METHODS: We analyzed 106 consecutive patients with HF complicating ischemic cardiomyopathy, in sinusal rhythm. LV strain, LV twist and LV torsion were measured by echocardiographic 2D-strain imaging. LV dyssynchrony was assessed using validated tissue Doppler parameters. Patients were divided into three groups: HF with normal LVEF (group 1), HF with reduced LVEF without LBBB (group 2) and with LBBB (group 3). RESULTS: LVEF, LV strain, LV torsion and LV twist were significantly better in group 1 (each p < 0.01). In group 3, LV torsion and LV twist were significantly lower compared to group 2 (0.80 +/- 0.4 vs. 1.21 +/- 0.23 degrees/cm, p = 0.007, and 5.18 +/- 2.4 vs. 8.31 +/- 1.5 degrees, p = 0.004, respectively), but LV strain and LVEF were not different between group 3 and 2 (-4.91 +/- 2.3 vs. -6.28 +/- 1.8%, p = 0.056, and 30.6 +/- 8.8 vs. 34.4 = 8.3%, p = 0.11, respectively). Cardiac dyssynchrony induces a reduction of all 2D-strain analyzed parameters (each p < 0.05). CONCLUSION: In HF complicating ischemic cardiomyopathy, LBBB and cardiac dyssynchrony induce a reduction of LV strain, torsion and twist. In patients with reduced LVEF, LBBB induces predominantly a significant reduction ofLV torsion and LV twist, while LV strain was apparently not influenced.

[The myocardial performance index (Tei-Index): correlation with seric NTproBNP levels in patients with dilated cardiomyopathy]. / Indexul de performanta miocardica globala (Tei): corelatia cu nivelul seric al NtproBNP in cardiomiopatia dilatativa.

UNLABELLED: A combined myocardial performance index (isovolumic contraction time plus isovolumic relaxation time divided by ejection time, 'Tei-Index') has been applied in the echocardiographic evaluation of patients with dilated cardiomyopathy (DCM). N-terminal pro brain natriuretic peptide (NTproBNP) is released from the left ventricular (LV) in response tomyocite stretch and is a powerful prognostic marker for heart failure. AIM: To assess the correlation between Tei index and NTproBNP level in patients with DCM. METHODS: Conventional echocardiography were performed in 50 consecutive patients with DCM, in sinus rhythm, concomitant with NTproBNP determination. Patients with paced rhythm and creatinine clearance < 40 mL/min were not included. Tei index was calculated. RESULTS: Simple regression analysis demonstrated a statistically significant linear correlation between NTproBNP and Tei index (r = 0.70, p < 0,001). NTproBNP had weaker relationship with pulmonary artery systolic pressure, indexed left atrial (LA) volume, LA volume, LV ejection fraction, early diastolic transmitral velocity (E) and no relationship with LA diameter, mitral E deceleration time, LV end-diastolic diameter. The area under the ROC curve for prediction of NTproBNP levels > 900 pg/mL was maxinal (0.76) for Tei index. The optimal Tei index cut-off for prediction of NTproBNP levels > 900 pg/mL was 0.77 (sensitivity = 84%, specificity = 82%). CONCLUSIONS: Tei index strongly correlates with NTproBNP in patients with DCM in sinus rhythm, and can be a simple and accurate predictor of the serum NTproBNP level.

Time movement timing parameters validation using tissue Doppler imaging in patients with dilated cardiomyopathy.

UNLABELLED: The aim of the study was to compare similar time-movement (TM) and tissue Doppler (TDI) timing parameters and to predict their value in assessment of systolic asynchrony for biventricular pacing indication. METHODS: 41 patients (pts) aged 56.4 +/- 11.2 years with dilated cardiomyopathy were included. PARAMETERS: QRS duration (QRSd); septal (S), posterior (P), lateral (L) and posterolateral (PL) wall delays, as the time from QRS onset to maximal wall contraction (parasternal, 4 chamber view and subcostal incidence); left ventricular mechanical delays (LVD) time interval from maximal contraction between interventricular septum and posterior (LVDp), lateral (LVD1) and posterolateral (LVDp1) wall, both in TM and TDI; TDI measurements were performed using both color and pulsed TDI (from onset of QRS to the end of S wave); isovolumic relaxation time (IRT) in each wall using TDI; An error parameter (Er) was assessed for each measurement as the difference in similar timing parameters TM-TDI. RESULTS: LVDp = 111 +/- 69ms, LVD1 = 132 +/- 62ms, LVDp1 = 151 +/- 77ms; 26 pts presented QRSd > 120 ms (LBBB), 15 pts had QRSd < 120 ms. LVD > 100 ms was found in 32 pts; LVD were significantly higher in LBBB pts. There was no correlation between QRSd and echocardiographic parameters. Er ranged from 0-80 ms. Er > 30 ms were found in pts with fragmented wall motion and IRT > 30 ms. The most delayed wall was PL (42% pts), L (38%) and P (30%). CONCLUSION: Intraventricular asynchronized contraction occurs even in pts with normal QRS duration; these changes can be easily and accurately detected using simple TM timing parameters. The most delayed site to be stimulated can be found either using TDI or TM.

Absence of correlation between QRS duration and echographic parameters of ventricular desynchronization. Can we still trust the electrocardiographic criteria?

UNLABELLED: The aim of the study was to assess if echographic ventricular desynchronization parameters measured in patients with dilated cardiomyopathy (DCM) and severe heart failure are correlated with the duration of the QRS on surface electrocardiogram. METHODS: This study included 51 pts aged 58.8 +/- 7.4 years with idiopathic DCM. The following parameters were measured: QRS duration; effective contraction time (ECT) measured as the interval between QRS onset and closure of aortic valve, interventricular delay (IVD) measured as the time between onset of aortic and pulmonary flow, left ventricular mechanical delay (LVD) as the time from maximal interventricular septum contraction and posterior wall contraction, posterior (P), lateral (L) and posterolateral (PL) wall delays, as the time from QRS onset to maximal wall contraction. Regional postsystolic contraction was defined in a given wall as the difference (contraction delay - ECT)> 50ms. RESULTS: 29 pts presented complete LBBB, 22 pts had QRS duration < 120 ms. 39 pts had a postsystolic contraction of the PL wall (32 pts of the L wall and 26 pts of the P wall). 16 pts with QRS duration <120 had a postsystolic contraction of the PL wall (as for the LBBB the rest of 39 pts). In 40 pts the sequence of regional ventricular contraction was: P-L-PL wall (16 pts with QRS<120). LVD was > 100 ms in 36 pts (26 pts with LBBB and 10 with QRS<120). 27 of pts with LBBB and 6 with QRS <120 ms presented IVD> 30ms. There was no correlation between the QRS duration and the parameters listed above. CONCLUSIONS: In DCM pts there is no correlation between the duration of the QRS and echocardiographic parameters of ventricular desynchronization. Mechanical ventricular de-synchrony can be observed in patients with QRS duration < 120 ms.

Global myocardial index in patients with multisite pacing.

UNLABELLED: Global myocardial index (GMI) is a sensitive echocardiographic indicator of overall cardiac function. The aim of this study was to compare the GMI changes induced by Bi-V pacing to the variations in clinical, electrocardiographic and echocardiographic parameters currently used for evaluation of ventricular resynchronization in order to test the potential marker of positive clinical response. PATIENTS AND METHODS: This study included 35 consecutive patients (pts), aged 65.7+/-7.5 years, implanted with an endocavitary Bi-V pacemaker for drug refractory severe heart failure. NYHA class was evaluated before implantation and at day 30. QRS duration (QRSd), echocardiographic interventricular delay (IVD), and GMI were determined in the paced and non-paced situation at day 1, 7 and 30 after implantation. RESULTS: NYHA class improved from 3.5+/-0.3 to 2.4+/-0.4 (p<0.01). GMI improved significantly (p<0.0001) after Bi-V in all pts from 1.25 +/- 0.5 to 0.77 +/- 0.34 and remained stable all along the study. GMI decrease (dGMI) in pts with NYHA functional class improvement > 0.5 was 0.52 +/- 0.16while dGMI in pts with NYHA functional class improvement < or = 0.5 was 0.21+/- 0.19. dGMI was statistically correlated with IVD shortening (r=0.67, p<0.0001) but not with QRSd shortening. CONCLUSION: The GMI improves during Bi-V pacing, mostly in responders pts and the improvement remains unchanged after the implant. The GMI decrease induced by Bi-V pacing is correlated with the IVD shortening and NYHA functional class improvement.