Diastolic Stunning as a Marker of Severe Coronary Artery Stenosis: Analysis by Speckle Tracking Radial Strain in the Resting Echocardiogram.

BACKGROUND: Two-dimensional speckle tracking (2DST) stress echocardiography detects postischemic myocardial diastolic stunning. However, the use of 2DST at rest for detecting diastolic stunning in ischemia is unclear. RESULTS: Thirty-nine patients (age = 65 ± 12 years; male/female = 34/5) with effort angina pectoris that was confirmed by stress myocardial perfusion scintigraphy were enrolled. Ischemic area (I) was determined in the middle LV short axial view using stress myocardial scintigraphy. The area opposite to it was defined as nonischemic area (non-I). Midventricular parasternal short-axis (SAX) radial strains were estimated using 2DST at rest on the following day. LV diastolic function was evaluated using diastolic index (DI, changes in the regional LV radial strain during diastole) and radial strain rate (SR) during early diastolic period. These parameters were compared between I and non-I before and 1 month after percutaneous coronary intervention (PCI) in the I of 3 coronary vessels. For the I, the DI was lower (38 ± 27 vs. 55 ± 27; P = 0.003) and SR was higher (-1.6 ± 0.6 vs. -1.9 ± 0.8; P = 0.007) than in non-I before PCI. One month after PCI, the DI and SR recovered to 53 ± 27 (P = 0.008) and -2.1 ± 0.8 (P = 0.006), respectively. Furthermore, the DI of the LAD and LCX significantly improved (P = 0.0004 and 0.002, respectively); the RCA area showed tendency to improve (P = 0.092), and the SR also improved (P < 0.05) in all areas after PCI. CONCLUSION: Diastolic stunning in ischemic areas can be detected using 2DST at rest and recover 1 month after PCI.

Transesophageal echocardiography for thrombus screening prior to left atrial catheter ablation.

BACKGROUND: Transesophageal echocardiography (TEE) is useful for detecting left atrial (LA) thrombus prior to percutaneous LA catheter ablation in patients with atrial fibrillation (AF). This study was designed to evaluate clinical predictors of LA thrombus and determine indications for TEE screening prior to LA ablation. METHODS AND RESULTS: The study consisted of 446 patients with drug-resistant AF who were scheduled to undergo initial LA ablation (age 59+/-11 years, 312 males, 136 persistent AF). TEE was performed in all cases within 24 h before ablation. We assessed clinical parameters including CHADS(2) score and echocardiographic parameters. LA thrombus was detected in 13 cases (2.9%) prior to LA ablation (67+/-8 years, 10 males, 12 persistent AF). In multiple logistic regression analysis, advanced age (odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0-1.2; P<0.05), persistent AF (OR 38.1, 95%CI 1.4-988; P<0.05) and structural heart diseases (OR 29.8, 95%CI 2.8-383; P<0.01) were independent positive predictors of LA thrombus prior to ablation, while CHADS(2) score and LA volume were not significant predictors. None of the 136 patients with paroxysmal lone AF whose age was below 60 years had LA thrombus prior to ablation. CONCLUSIONS: It might be reasonable to omit TEE as a screening examination for LA thrombus prior to LA ablation in younger paroxysmal lone AF patients.

Right bundle branch block and impaired left ventricular function as evidence of a left ventricular conduction delay.

BACKGROUND: The indications and efficacy of cardiac resynchronization therapy (CRT) have not been sufficiently clarified in patients with right bundle branch block (RBBB). METHODS AND RESULTS: This study included 55 patients with normal QRS morphology and duration (Control-Gr) and 49 patients with complete RBBB (CRBBB-Gr). Using tissue Doppler imaging, the time difference (TD) between the electromechanical delay of the septal wall, left ventricular (LV) lateral wall, and right ventricular free wall were measured. Using tissue tracking imaging, the coefficient of the time variation from the beginning of the QRS to the peak displacement time of 6 regions of the LV (CV-PMDLV) was calculated. The TD between the septal wall and that of the LV lateral wall (TDSEPT-LAT) did not differ between the Control-Gr and RBBB-Gr. However, a significant difference was found in the TDSEPT-LAT between the CRBBB patients with LV systolic dysfunction (ejection fraction (EF) < or =50%) and those with normal LV function (EF >50%; p<0.001). The CV-PMDLV was greater in the CRBBB patients with LV systolic dysfunction than in those with a normal LV function (p<0.05). The RBBB-Gr patients with LV dysfunction and a great TDSEPT-LAT, improved clinically after the CRT. CONCLUSIONS: The presence of RBBB and LV dysfunction may indicate LV dyssynchrony and a heterogeneous mechanical dysfunction.

Maximum ventricular dyssynchrony predicts clinical improvement and reverse remodeling during cardiac resynchronization therapy.

BACKGROUND: Tissue synchronization imaging (TSI) and tissue tracking imaging (TTI) might facilitate the evaluation of ventricular dyssynchrony. METHODS: In 22 patients, TSI and TTI were performed before and < 1 month after onset of cardiac resynchronization therapy (CRT). With TSI guidance, maximum left ventricular (LV) intraventricular conduction delay (IVCDmax) was the greatest difference in time-to-peak velocity between septum and lateral wall. IVCD between the basal septum and lateral wall (IVCDbase) was also measured. Using TTI, the mean peak myocardial displacement of the basal septal and lateral walls (PMDbase), and the temporal coefficient of variation of the PMD in six LV regions (CV-PMDLV) were measured. The patients were divided into responders (whose LV end-systolic volume decreased by >/= 15% during a 27 +/- 9 months follow-up) and nonresponders. RESULTS: Before CRT, IVCDbase was similar in both groups, and remained unchanged within the 1st month of CRT in both groups. However, before CRT, IVCDmax was greater in responders than in nonresponders (P < 0.05), and decreased only in the responders during CRT (P < 0.05). No significant difference was observed in PMDbase or CV-PMDLV between the two groups, before or during CRT. CONCLUSIONS: TSI was useful to measure IVCDmax. A greater IVCDmax before CRT that decreased shortly after onset of CRT may predict long-term clinical improvement in CRT recipients.

Tissue Doppler imaging and strain Doppler imaging as modalities for predicting clinical improvement in patients receiving biventricular pacing.

BACKGROUND: The purpose of this study was to determine the utility and efficacy of tissue Doppler imaging (TDI) and strain Doppler imaging (SDI) for evaluating ventricular synchrony and function, and for predicting the long-term clinical improvement in patients undergoing biventricular pacing (BVP). METHODS AND RESULTS: TDI and SDI were performed before and <1 month after initiating BVP in 17 patients with advanced heart failure. An intraventricular conduction delay between the left ventricular (LV) septal and lateral walls was measured by TDI. The average LV strain (LV-strain) was calculated from data obtained at the center of 6 regions of the LV (base and mid-point between the basal and apical portions, and the mid-point between these 2 points on the septal and lateral walls). During a 23+/-7 month follow-up period, 12 patients improved clinically and did not require re-hospitalization for heart failure (responder group), but the remaining 5 did not improve (nonresponder group). Before BVP, the intraventricular conduction delay was greater in the responder group than in the nonresponder group (p<0.01), but after BVP, it did not differ between the 2 groups. LV-strain improved after BVP in the responder group but not in the nonresponder group (p<0.05). CONCLUSION: A high intraventricular conduction delay before BVP and decreased strain shortly after BVP may predict long-term clinical improvement in patients undergoing this treatment.