Combined baseline strain dyssynchrony index and its acute reduction predicts mid-term left ventricular reverse remodeling and long-term outcome after cardiac resynchronization therapy.

The objective of this study was to test the hypothesis that combining assessment of baseline radial strain dyssynchrony index (SDI), that expressed both left ventricular (LV) dyssynchrony and residual myocardial contractility, and of acute changes in this index can yield more accurate prediction of mid-term responders and long-term outcome after cardiac resynchronization therapy (CRT). Radial SDI for 75 CRT patients was calculated as the average difference between peak and end-systolic speckle tracking strain from 6 segments of the mid-LV short-axis view before and 8 ± 2 days after CRT. Mid-term responder was defined as ≥ 15% decrease in LV end-systolic volume 6 ± 2 months after CRT. Long-term outcome was tracked over 5 years. Baseline radial SDI ≥ 6.5% is considered predictive of responder and favorable outcome, as previously reported. Acute reduction in radial SDI ≥ 1.5% was found to be the best predictor of mid-term responders with CRT. Furthermore, patients with acute reductions in radial SDI ≥1.5% were associated with a significantly more favorable long-term outcome after CRT than those with radial SDI <1.5% (log rank P < 0.001). An important findings were that baseline radial SDI ≥6.5% and acute reductions in radial SDI ≥ 1.5% in 42 patients were associated with the highest event-free survival rate of 92%, whereas, 21 patients corresponding values of <6.5% and <1.5% were associated with low event-free survival rate of 46% (log rank P < 0.001). Combined assessment of baseline radial SDI and its acute reduction after CRT may have clinical implications for predicting responders and thus patients' care.

Impact of preserved myocardial contractile function in the segments attached to the papillary muscles on reduction in functional mitral regurgitation.

BACKGROUND: Effectiveness of functional mitral regurgitation (FMR) in heart failure patients is of growing importance for patient prognosis. The purpose of this study was to investigate whether regional myocardial contractile function as assessed by tissue Doppler strain rate imaging can predict reduction in FMR caused by dobutamine. METHODS: Fifty-one patients with depressed left ventricular (LV) ejection fraction (32 ± 9%) secondary to dilated cardiomyopathy and FMR underwent evaluation of effective regurgitant orifice (ERO) of FMR, mitral valve deformation, global LV remodeling, and regional myocardial contractile function assessed by longitudinal peak systolic strain rate (Ssr) in 6 mid-LV segments from standard apical views. We also determined the average Ssr of segments attached to the papillary muscles, that is, the inferior, inferolateral, and anterolateral segments (PM segments Ssr). Low-dose (10 µg/kg per minute) dobutamine-induced reduction in ERO was compared with baseline variables. RESULTS: Baseline valve tenting was associated with dobutamine-induced reduction in ERO (r = -0.30, P < 0.05). Receiver operating characteristic curve analysis showed that baseline valve tenting, LV sphericity index, inferior Ssr, inferolateral Ssr, and PM segments Ssr were predictors of dobutamine-induced ≥30% reduction in ERO. Importantly, only PM segments Ssr predicted dobutamine-induced ≥20% reduction in valve tenting with area under the curve of 0.67 (P < 0.05). CONCLUSIONS: Preserved myocardial contractile function in the segments attached to the PMs was associated with dobutamine-induced reduction in mitral valve tenting and FMR, suggesting that our findings are important for improvement in cardiac function and FMR with medical treatment.

Relation between strain dyssynchrony index determined by comprehensive assessment using speckle-tracking imaging and long-term outcome after cardiac resynchronization therapy for patients with heart failure.

Strain dyssynchrony index (SDI), which was a marker of dyssynchrony and residual myocardial contractility, can predict left ventricular reverse remodeling short-term after cardiac resynchronization therapy (CRT). We investigated SDI-predicted long-term outcome after CRT in patients with heart failure (HF). We studied 74 patients with HF who underwent CRT. SDI was calculated as the average difference between peak and end-systolic strain from 6 segments for radial and circumferential SDIs and 18 segments for longitudinal SDI using 2-dimensional speckle-tracking strain. Based on our previous findings, the predefined cutoff for significant dyssynchrony and residual myocardial contractility was a radial SDI ≥6.5%, a circumferential SDI ≥3.2%, and a longitudinal SDI ≥3.6%. The predefined principal outcome variable was the combined end point of death or hospitalization owing to deteriorating HF. Long-term follow-up after CRT was tracked over 4 years. The primary end point of prespecified events occurred in 14 patients (19%). An association with a favorable long-term outcome after CRT was observed in patients with significant radial, circumferential, and longitudinal SDIs (p <0.001, <0.005, and 0.010 vs patients without significant SDIs, respectively). Furthermore, cardiovascular event-free rate after CRT in patients with positivity of 3 for the 3 SDIs was 100% better than that in patients with positivity of 1 (52%, p <0.005) or 0 (31%, p <0.001) for the 3 SDIs. In conclusion, SDIs can successfully predict long-term outcome after CRT in patients with HF. Moreover, the approach combining the 3 types of SDI leads to a more accurate prediction than the use of individual parameters. These findings may have clinical implications in patients with CRT.

Impact of left ventricular afterload on longitudinal dyssynchrony in patients with severe aortic stenosis and preserved ejection fraction.

BACKGROUND: The purpose of this study was to investigate whether patients with severe aortic stenosis (AS) and preserved ejection fraction (EF) have dyssynchrony and whether it improves after aortic valve replacement (AVR). METHODS AND RESULTS: We studied 30 consecutive patients with severe AS and preserved EF undergoing AVR. For baseline comparison, we studied 17 EF-matched patients with mild-to-moderate AS, and 18 EF-matched normal volunteers. Longitudinal dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain in apical 4- and 2-chamber views at the basal- and mid-levels. Radial and circumferential dyssynchrony was determined as the difference for time-to-peak strain between the anteroseptum and posterior wall from the mid-left ventricular (LV) short-axis view. Each of the myocardial functions was also evaluated by averaging each peak systolic strain. Longitudinal dyssynchrony and function in patients with severe AS was significantly worse than in the patients with mild-to-moderate AS and the controls (94 ± 46 vs. 66 ± 18 ms* and 52 ± 17 ms*, and 12.5 ± 3.7% vs. 16 ± 3.5%* and 18.7 ± 3.7%*, respectively, *P<0.05, vs. severe AS). In contrast, radial and circumferential dyssynchrony were similar for the 3 groups. Importantly, the dyssynchrony of patients with severe AS significantly improved after AVR from 94 ± 46 ms to 68 ± 22 ms (P<0.005). CONCLUSIONS: Significant longitudinal dyssynchrony was present in patients with severe AS and preserved EF, and it improved after AVR.

Mechanical left ventricular dyssynchrony in heart failure patients with narrow QRS duration as assessed by three-dimensional speckle area tracking strain.

The aim of this study was to assess whether heart failure (HF) patients with narrow QRS durations have mechanical left ventricular (LV) dyssynchrony compared to those with wide QRS durations and with normal subjects. The strain dyssynchrony index with 3-dimensional area tracking (ASDI) was used, which represents mechanical LV dyssynchrony and residual endomyocardial function from circumferential as well as longitudinal directions. The study included 79 subjects: 32 HF patients with ejection fractions ≤ 35% and narrow QRS durations (<120 ms) and 22 with ejection fractions ≤ 35% and wide QRS durations (≥ 120 ms), all candidates for cardiac resynchronization therapy, and 25 normal controls. ASDI was calculated as the average difference between peak and end-systolic area strain of LV endocardium obtained using 3-dimensional speckle-tracking imaging using 16 LV segments (≥ 3.8% predefined as significant). ASDI in HF patients with narrow QRS durations was lower than in their counterparts with wide QRS durations (2.5 ± 1.3% vs 4.2 ± 1.2%, p <0.001) but higher than in normal controls (2.5 ± 1.3% vs 0.73 ± 0.53%, p <0.001). Furthermore, the prevalence of significant ASDI in HF patients with narrow QRS durations was significantly higher than in normal controls (22% vs 0%, p = 0.01) but significantly lower than in HF patients with wide QRS durations (22% vs 59%, p <0.01). In conclusion, HF patients with narrow QRS durations have LV dyssynchrony. These observations suggest that the use of 3-dimensional speckle area tracking strain might be extended to HF patients with narrow QRS durations who are being considered as potential candidates for cardiac resynchronization therapy.

Strain dyssynchrony index determined by three-dimensional speckle area tracking can predict response to cardiac resynchronization therapy.

BACKGROUND: We have previously reported strain dyssynchrony index assessed by two-dimensional speckle tracking strain, and a marker of both dyssynchrony and residual myocardial contractility, can predict response to cardiac resynchronization therapy (CRT). A newly developed three-dimensional (3-D) speckle tracking system can quantify endocardial area change ratio (area strain), which coupled with the factors of both longitudinal and circumferential strain, from all 16 standard left ventricular (LV) segments using complete 3-D pyramidal datasets. Our objective was to test the hypothesis that strain dyssynchrony index using area tracking (ASDI) can quantify dyssynchrony and predict response to CRT. METHODS: We studied 14 heart failure patients with ejection fraction of 27 ± 7% (all≤35%) and QRS duration of 172 ± 30 ms (all≥120 ms) who underwent CRT. Echocardiography was performed before and 6-month after CRT. ASDI was calculated as the average difference between peak and end-systolic area strain of LV endocardium obtained from 3-D speckle tracking imaging using 16 segments. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, Yu Index, and two-dimensional radial dyssynchrony by speckle-tracking strain. Response was defined as a ≥15% decrease in LV end-systolic volume 6-month after CRT. RESULTS: ASDI ≥ 3.8% was the best predictor of response to CRT with a sensitivity of 78%, specificity of 100% and area under the curve (AUC) of 0.93 (p < 0.001). Two-dimensional radial dyssynchrony determined by speckle-tracking strain was also predictive of response to CRT with an AUC of 0.82 (p < 0.005). Interestingly, ASDI ≥ 3.8% was associated with the highest incidence of echocardiographic improvement after CRT with a response rate of 100% (7/7), and baseline ASDI correlated with reduction of LV end-systolic volume following CRT (r = 0.80, p < 0.001). CONCLUSIONS: ASDI can predict responders and LV reverse remodeling following CRT. This novel index using the 3-D speckle tracking system, which shows circumferential and longitudinal LV dyssynchrony and residual endocardial contractility, may thus have clinical significance for CRT patients.

Nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage: case report.

A 63-year-old man was admitted to our hospital with a complaint of right lateroabdominal pain. He was diagnosed with metastatic colon cancer, and then developed multiple brain embolic infarctions 7 days after admission. Transesophageal echocardiography showed that mobile, echo-dense masses were attached to the anterior and posterior mitral valve leaflet. Furthermore, there was a thrombus in the left auricular appendage despite sinus rhythm. These findings led to a diagnosis of suspected infectious endocarditis with subsequent multiple brain infarctions. The patient's general condition worsened and he died 13 days after admission. An autopsy was performed, and, while poorly differentiated cancer was observed in multiple organs, no primary tumor could be identified. Histological analysis showed that the masses of the mitral valve consisted mainly of fibrin without bacteria or oncocytes. This patient was therefore diagnosed with nonbacterial thrombotic endocarditis associated with cancer of unknown origin complicated with thrombus in the left auricular appendage.

Exercise-induced left bundle branch block and subsequent mechanical left ventricular dyssynchrony--resolved with pharmacological therapy.

A 53-year-old man with depressed ejection fraction (EF) of 35% and QRS width of 88 ms at rest was admitted to our institution with a complaint of exertional chest discomfort and dyspnea. During treadmill exercise, left bundle-branch block (LBBB) with a QRS width of 152 ms occurred at a heart rate of 100 bpm. During LBBB, the patient showed significant mechanical dyssynchrony as evidenced by a two-dimensional speckle tracking radial strain of 260 ms (≥ 130 ms), defined as the time difference between anterior-septum and posterior wall. Five-month after carvedilol and candesartan administration, EF had improved to 49% and LBBB did not occur until a heart rate of 126 bpm was attained during treadmill exercise. It appears that pharmacological therapy may be useful for patients with heart failure and exercise-induced LBBB.

Comparison of mitral valve area by pressure half-time and proximal isovelocity surface area method in patients with mitral stenosis: effect of net atrioventricular compliance.

AIMS: The aim of this study was to test the hypothesis that, unlike calculation of the mitral valve area (MVA) with the pressure half-time method (PHT), the proximal isovelocity surface area method (PISA) is not affected by changes in net atrioventricular compliance (C(n)). METHODS AND RESULTS: We studied 51 patients with mitral stenosis (MS) from two centres. MVA was assessed with the PISA (MVA(PISA)), PHT (MVA(PHT)), and planimetry (MVA(PLN), serving as the gold standard) method. C(n) was calculated with a previously validated equation using 2D echocardiography. MVA(PISA) closely correlated with MVA(PLN) (r = 0.96, P < 0.0001), while MVA(PHT) and MVA(PLN) showed a weaker but still good correlation (r = 0.69, P < 0.0001). The correlation between MVA(PHT) and MVA(PLN) for patients with C(n) between 4 and 6 mL/mmHg (considered to be normal) was excellent (r = 0.93, P < 0.0001), but that for patients with C(n) of less than 4 or more than 6 mL/mmHg was not as good (r = 0.64, P < 0.0001). Importantly, a significant inverse correlation was detected between the percentage difference among MVA(PHT), MVA(PLN), and C(n) (r = -0.77, P < 0.0001), but the line of fit was nearly flat for the percentage difference among MVA(PISA), MVA(PLN), and C(n) (r = 0.1, P = 0.388). CONCLUSION: MVA calculated with both the PISA and PHT methods correlated well with MVA calculated with the planimetry method. However, the PISA rather than PHT is recommended for patients with MS and extreme C(n) values because PISA, unlike PHT, is not affected by changes in C(n).

Utility of comprehensive assessment of strain dyssynchrony index by speckle tracking imaging for predicting response to cardiac resynchronization therapy.

The strain delay index is reportedly a marker of dyssynchrony and residual myocardial contractility. The aim of this study was to test the hypothesis that a relatively simple version of the strain dyssynchrony index (SDI) can predict response to cardiac resynchronization therapy (CRT) and that combining assessment of radial, circumferential, and longitudinal SDI can further improve the prediction of responders. A total of 52 patients who underwent CRT were studied. The SDI was calculated as the average difference between peak and end-systolic strain from 6 segments for radial and circumferential SDI and 18 segments for longitudinal SDI. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, the Yu index, and radial dyssynchrony by speckle tracking strain. Response was defined as a ≥15% decrease in end-systolic volume after 3 months. Of the individual parameters, radial SDI ≥6.5% was the best predictor of response to CRT, with sensitivity of 81%, specificity of 81%, and an area under the curve of 0.87 (p <0.001). Circumferential SDI ≥3.2% and longitudinal SDI ≥3.6% were also found to be predictive of response to CRT, with areas under the curve of 0.81 and 0.80, respectively (p <0.001). Moreover, radial, circumferential, and longitudinal SDI at baseline were correlated with reduction of end-systolic volume with CRT. In addition, the response rate in patients with 3 positive SDIs was 100%. In contrast, rates in patients with either 1 or no positive SDIs were 42% and 22%, respectively (p <0.005 and p <0.001 vs 3 positive SDIs). In conclusion, the SDI can successfully predict response to CRT, and the combined approach leads to more accurate prediction than using individual parameters.

Dobutamine-induced improvement in inferior myocardial contractile function predicts reduction in functional mitral regurgitation: a study using tissue Doppler strain rate imaging.

BACKGROUND: left ventricular (LV) remodeling can increase tethering force to mitral valve and functional mitral regurgitation (FMR). Because the relationship between FMR and regional myocardial function has not been quantitatively evaluated, we conducted a quantitative investigation of this association. METHODS AND RESULTS: the effective regurgitant orifice (ERO) of FMR in 51 patients with depressed LV ejection fraction (32±9%) secondary to ischemic or nonischemic cardiomyopathy was compared with mitral deformation (valve and annulus), global LV remodeling (volume indices, function, and sphericity), and regional myocardial contractile function, as assessed by longitudinal peak systolic strain rate (Ssr) in LV anterior, anteroseptal, inferoseptal, inferior, inferolateral, and anterolateral segments at rest. Low-dose dobutamine (10 µg/kg per minute)-induced changes in ERO were compared with changes in the variables. Multivariable analysis identified the predictors of ERO at rest as mitral valvular tenting (ß=0.062; P<0.001), Ssr in the inferior segment (inferior Ssr) (ß=-0.178; P<0.001), and LV sphericity (ß=0.414; P=0.001) and the predictors of valvular tenting at rest as inferior Ssr (ß=-1.680; P<0.001), LV end-systolic volume index (ß=0.022; P=0.001), and LV sphericity (ß=3.886; P=0.012). Furthermore, dobutamine-induced reduction in ERO was predicted by reduction in valvular tenting (ß=0.087; P<0.001) and increase in inferior Ssr (ß=-0.082; P<0.001), and dobutamine-induced reduction in valvular tenting was predicted by increase in inferior Ssr (ß=-0.860; P<0.001). CONCLUSIONS: inferior regional myocardial dysfunction was quantitatively associated with mitral valvular tenting and FMR. Moreover, improvement with dobutamine of inferior myocardial contractile function attenuated valvular tenting and FMR. Inferior myocardial contractile function can affect the configuration of the mitral apparatus and predict FMR severity.

Myocardial contractile function in the region of the left ventricular pacing lead predicts the response to cardiac resynchronization therapy assessed by two-dimensional speckle tracking echocardiography.

BACKGROUND: The aim of this study was to test the impact of posterolateral myocardial systolic function on response to cardiac resynchronization therapy (CRT). METHODS: Forty patients were studied before and 4 +/- 2 months after CRT. Dyssynchrony was defined as anteroseptal wall-to-posterior wall delay (> or = 130 ms) caused by speckle-tracking radial strain. The average longitudinal strain in 4 posterior and lateral segments (epsilon-pl) in which the left ventricular pacing lead was positioned was calculated by automated functional imaging. Response to CRT was defined as a > or = 15% decrease in end-systolic volume. RESULTS: The negative value of epsilon-pl in responders was significantly higher than that in nonresponders at baseline (-7.8 +/- 6.9% vs -2.1 +/- 4.9%, P < .01). Combining dyssynchrony with epsilon-pl < -7.8% was more effective for predicting response to CRT than dyssynchrony parameters alone (92% vs 75%). CONCLUSION: The addition of posterolateral myocardial systolic function to the measurement of dyssynchrony appears to be of value for predicting response to CRT.

Isolated true parachute mitral valve in an asymptomatic elderly patient.

We report the extremely rare case of a 73-year-old asymptomatic patient who has an isolated true parachute mitral valve (PMV). In the echocardiographic examination, the parasternal long-axis view showed a single papillary muscle. The short-axis view revealed the presence of a symmetric mitral valve orifice with all chordae attaching to a large anterolateral papillary muscle. Because detailed examination did not reveal the presence of other complications, this patient was diagnosed as an isolated true PMV.