Intracardiac Flow Analysis: Techniques and Potential Clinical Applications.

Analysis of intracardiac flows has gained increasing interest in the last years. This analysis has become possible due to the development of technologies for noninvasive cardiovascular imaging, which allow visualization and quantitation of intracardiac flow dynamics. Several studies have shown that abnormalities in cardiac function are related to changes in intracardiac vortical flows. Thus, analysis of cardiac vortex has been used for better understanding of the pathophysiology in many heart diseases and to test initial clinical hypotheses. The aims of this review are to introduce the reader to the topic of intracardiac flow dynamics, to briefly describe current cardiac imaging techniques for analysis of the intracardiac vortex, and to indicate potential clinical applications of a vortex-based approach to the study of cardiac function.

Urgent Myocardial Revascularization in Non ST-Segment Elevation Acute Myocardial Infarction Guided by Speckle Tracking Echocardiography: A Challenging Interventional Decision-Making.

A 68-year-old man with a non-ST elevation myocardial infarction (NSTEMI) presented with a low risk profile indicating invasive revascularization within 72 h. However, left ventricular (LV) global longitudinal strain (GLS) calculated by two-dimensional speckle tracking echocardiography (2D-STE) in the Emergency Room showed substantial myocardial infarction. Therefore, urgent reperfusion therapy was decided and delivered within 30 min from hospital admission. LV GLS fully recovered after the invasive procedure and the final infarct size was 7%. This case shows that very early revascularization in NSTEMI patients can be guided by 2D-STE and might be considered for those patients with substantial LV myocardial infarction.

Device closure of 'complex' postinfarction ventricular septal defect.

Ventricular septal defect (VSD) is a life-threatening complication of acute myocardial infarction (MI), resulting in high mortality rate even in the case of a timely approach by surgical repair. Transcatheter closure is nowadays a reliable alternative to surgery, although currently deemed challenging or unsuitable in large and complex VSD. This article reports on a successful transcatheter approach in a critically ill patient with subacute right coronary-related, complex postinfarction VSD. In this patient, two sequentially deployed Amplatzer Septal Occluder devices stabilized the clinical conditions and hemodynamic parameters.

Ventricular mechanical asynchrony in patients with different degrees of systolic dysfunction: results from AVE Registry by the Italian Society of Cardiovascular Echography (SIEC).

OBJECTIVE: The aim of the study was to compare the prevalence of interventricular and intraventricular asynchrony in patients with different degrees of left ventricular (LV) dysfunction. METHODS: We enrolled 182 patients (male 79%, mean age 64 +/- 11 years) with LV ejection fraction (EF) < 50% and identified two groups: Group A (n = 79) with mild-to-moderate LV dysfunction (EF between 36% and 49%) and Group B (n = 103) with severe dysfunction (EF 102 msec) did not differ between groups either (29.9% vs. 35.9%; P = 0.39). CONCLUSIONS: The prevalence of intraventricular asynchrony is independent of the LV systolic dysfunction severity. This could indicate the potential role of cardiac resynchronization therapy in patients with mild-moderate systolic dysfunction.

Comparison of myocardial deformation and velocity dyssynchrony for identification of responders to cardiac resynchronization therapy.

AIMS: It is unclear whether myocardial velocity or deformation indices of dyssynchrony are better at predicting response to cardiac resynchronization therapy (CRT). Therefore, two indices of left ventricular (LV) dyssynchrony based on myocardial velocity and deformation were compared to predict success of CRT. METHODS AND RESULTS: Sixty patients with dilated cardiomyopathy, New York Heart Association class III-IV, LV ejection fraction (EF) < or =35%, QRS >120 ms underwent CRT. The standard deviation of the averaged time-to-peak longitudinal negative strain (Tepsilon-SD) and positive systolic velocity (Tv-SD) of 12 LV segments were calculated before and after 6 months of CRT. Responders were defined at month 6 by > or =20% EF increase and/or > or =15% end-systolic volume (ESV) decrease with respect to baseline. On univariable analysis, baseline Tepsilon-SD and Tv-SD were both significantly associated with CRT response; however, the area under the receiver operating characteristic curve was better for Tepsilon-SD. On bivariable analysis, only Tepsilon-SD retained an independent prognostic value for CRT response. Results of the analysis did not change when the logistic models were adjusted for aetiology. CONCLUSION: Baseline dyssynchrony of longitudinal myocardial peak deformation (Tepsilon-SD) appears to be better than dyssynchrony of longitudinal myocardial peak systolic velocities (Tv-SD) for the identification of CRT responders.

Acute left ventricular dyssynchrony improvement predicts long-term benefit from cardiac resynchronization therapy.

STUDY OBJECTIVE: To evaluate the relationship between acute response to cardiac resynchronization therapy (CRT) and long-term clinical outcome in patients with drug refractory heart failure. METHODS AND RESULTS: In 28 patients undergoing CRT implant, left ventricular (LV) dyssynchrony was evaluated by tissue Doppler imaging (TDI)-derived longitudinal strain by mean of septum-lateral basal asynchrony index (S-Li) and basal delayed longitudinal contraction (DLC). TDI measurements were made before, and 30 minutes and 1 year after implant. Baseline and 1-year follow-up New York Heart Association (NYHA) functional class, 6-minute walking test (6-MWT) distance, and quality of life (QoL) score were measured. Responders (n = 22) were defined by a >/= 1 decrease in NYHA functional class and 6-MWT >/= 25% at 1 year. At baseline, no differences were observed between responders and nonresponders in clinical and echocardiographic measurements. LV dyssynchrony acutely recovered only in responders 30 minutes after implantation, with a significant reduction in S-Li and DLC. Moreover, the percent decreases in S-Li and DLC were highly correlated with those observed in NYHA class (r = 0.70, and r = 0.81, respectively, P < 0.001), 6-MWT (r = 0.59, and r = 0.57, respectively, P < 0.001 and P < 0.01), and QoL score (r = 0.71, and r = 0.83, respectively, p < 0.001) at 1-year follow-up. CONCLUSIONS: Acute recovery of LV intraventricular dyssynchrony is a major discriminator between responders and nonresponders to CRT, which strongly correlates with a favorable long-term clinical outcome.

Left intraventricular myocardial deformation dyssynchrony identifies responders to cardiac resynchronization therapy in patients with heart failure.

AIMS: We tested the hypothesis that dyssynchrony of left ventricular (LV) myocardial deformation evaluated by ultrasound can predict success of cardiac resynchronization therapy (CRT) in patients with heart failure (HF). METHODS AND RESULTS: Thirty-seven patients with dilated cardiomyopathy, New York Heart Association class III-IV, LV ejection fraction (EF) < or =35%, QRS > 120 ms were studied before, at pre-discharge, and after 3 and 6 months of CRT. The M-mode peak septal-to-posterior wall motion and thickening delay (SPWMD and SPWTD, ms) and the standard deviation of the averaged time-to-peak strain (TPS-SD, ms) of 12 middle and basal LV segments obtained from the three standard apical views were calculated. Responders were defined at month 6 by > or =20% EF increase and/or > or =15% end-systolic volume (ESV) decrease with respect to baseline. Baseline SPWTD (not SPWMD) and TPS-SD differentiated responders from non-responders with good accuracy and reproducibility. A value > or =194 ms for SPWTD and > or =60 ms for TPS-SD was significantly associated with responder identification. Baseline dyssynchrony parameters correlated significantly with EF (r = 0.53 for SPWTD and r = 0.86 for TPS-SD) and ESV variations (r = -0.42 for SPWTD and r = -0.73 for TPS-SD). CONCLUSION: Patients with chronic HF should undergo ultrasound evaluation to quantify dyssynchrony of LV myocardial deformation, which would help identifying CRT responders.

Left ventricular functional recovery during cardiac resynchronization therapy: predictive role of asynchrony measured by strain rate analysis.

Cardiac resynchronization therapy (CRT) improves myocardial performance in patients with heart failure (HF) and left bundle-branch block (LBBB). Tissue Doppler echocardiography (TDE) has already been used to guide the selection of candidates for CRT. The objective of this study is to correlate the effects of CRT on left ventricular (LV) systolic function with wall motion synchrony assessed by TDE. High frame TDE data were obtained in 15 patients (mean age = 68.9 years, 11 men) with LBBB (QRS = 163 +/- 13 ms) to derive temporal intraventricular horizontal asynchrony indexes, expressed as the time difference at the onset of shortening between the septum and the lateral (S-L) and antero-inferior (A-I) walls, and measure the amount of delayed longitudinal contraction (DLC) within the LV. All measurements were made at baseline, 24 hours after implantation, and at 1 year of follow-up. The results show that LV ejection fraction (EF) increased from 25 +/- 6.2% at baseline to 36.9 +/- 7.9% at 1 year, and was strongly related to DLC, expressed either by time duration (DLCd, r =-0.51; P < 0.0001) or percent of the basal segments (%DLC, r =-0.50; P < 0.001). New York Heart Association functional class, which decreased from 3.6 +/- 0.5 to 2.3 +/- 0.8, was correlated with %DLC (r = 0.50) and DLCd (r = 0.48, P < 0.001). Weaker correlations were found between LVEF and S-Li (r =-0.40) and between NYHA and S-Li (r = 0.40). It is concluded that DLC was the best among intraventricular asynchrony indexes in predicting increases in LVEF after CRT. DLC may be useful to identify responders to CRT.

Sequential biventricular resynchronization optimized by myocardial strain rate analysis: a case report.

We report the case of a patient with severe left ventricular systolic dysfunction and left bundle branch block in whom cardiac resynchronization therapy (CRT) was optimized by tissue Doppler imaging. A horizontal mechanical asynchrony index was derived from tissue Doppler regional longitudinal strain rate profiles as the time difference at the onset of shortening between septum, lateral, anterior and inferior walls. The interventricular delay was modulated in order to achieve the smallest asynchrony index; on the basis of this parameter a sequential (S)-CRT with a left ventricular pre-excitation of 20 ms was definitively programmed. This optimized S-CRT was followed by an acute improvement in systolic cardiac performance and by a long-term (12 months) clinical benefit as well as by a documented decrease in LV chamber size due to a true reverse remodeling effect. Thus, in some patients S-CRT may be more effective than conventional CRT. Tissue Doppler-derived strain rate analysis can provide information on the degree of left intraventricular asynchrony allowing the modulation of a tailored interventricular delay.