Left Ventricular Stimulation With Electrical Latency Predicts Mortality in Patients Undergoing Cardiac Resynchronization Therapy.

OBJECTIVES: This study sought to evaluate the prognostic value of the time interval from left ventricular (LV) pacing to the earliest onset of QRS complex (S-QRS) for long-term clinical outcomes in patients who underwent cardiac resynchronization therapy (CRT). BACKGROUND: The electrical latency during LV pacing evaluated by S-QRS is associated with local tissue property, and the S-QRS ≥37 ms has been previously proposed as an independent predictor of mechanical response to CRT. METHODS: This study included 82 consecutive patients with heart failure with reduced LV ejection fraction (≤35%) and a wide QRS complex (≥120 ms) who underwent CRT. Patients were divided into a short S-QRS group (SS-QRS; <37 ms) and a long S-QRS group (LS-QRS; ≥37 ms). The primary endpoint was total mortality, including LV assist device implantation or heart transplantation, whereas the secondary endpoint was total mortality or HF hospitalization. RESULTS: S-QRS was 25.9 ± 5.3 ms in SS-QRS and 51.5 ± 13.7 ms in LS-QRS (p < 0.01), and baseline QRS duration and electrical activation at the LV pacing site (i.e., Q-LV) were similar. During mean follow-up of 44.5 ± 21.1 months, 24 patients (29%) reached the primary endpoint, whereas the secondary endpoints were observed in 47 patients (57%). LS-QRS had significantly worse event-free survival for both endpoints. LS-QRS was an independent predictor of total mortality (hazard ratio: 2.6; 95% confidence interval: 1.11 to 6.12; p = 0.03) and the secondary composite events (hazard ratio: 2.4; 95% confidence interval: 1.31 to 4.33; p < 0.01). CONCLUSIONS: The S-QRS ≥37 ms at the LV pacing site was a significant predictor of total mortality and HF hospitalization. S-QRS-guided optimal LV lead placement is critical in patients who receive CRT.

Right atrial conduction time for predicting coexistent typical atrial flutter in patients with paroxysmal atrial fibrillation.

INTRODUCTION: Screening of coexistent typical atrial flutter (AFL) in patients with atrial fibrillation (AF) is sometimes challenging. This study investigated whether a prolonged right atrial conduction time (RACT) estimated by tissue Doppler imaging (TDI) predicts patients with concomitant AFL and AF. METHODS AND RESULTS: We retrospectively analyzed 398 patients (mean age: 61.6 years, 73.4% men) undergoing catheter ablation of paroxysmal AF. The patients were classified into two groups according to whether they had evidence of AFL (N = 122, 30.7%) determined by a clinical observation (N = 68), induction during procedures (N = 33), or AFL recurrence after procedures (N = 21) or not (N = 276, 69.3%). The preoperative RACT, defined as a longer duration between the onset of the P-wave and peak A'-wave on the right atrial lateral wall or septal wall, and total atrial conduction time (TACT), defined as the same time duration on the left atrial lateral wall, were evaluated in all patients. Patients with evidence of AFL had a significantly longer RACT than those without AFL (p < .001). A multiple logistic regression and receiver operator characteristics curve analysis revealed the ratio of the RACT and TACT (RACT/TACT) was the independent and most superior accurate cofounder for predicting evidence of AFL (area under the curve: 0.867). When adding a discriminator of an RACT/TACT ≧ 93% into the conventional screening, 98.4% of the patients with evidence of AFL were estimated to be treated during the initial procedures. CONCLUSION: The estimated RACT/TACT using the TDI may be useful for predicting patients with concomitant AFL in patients with AF.

Time interval from left ventricular stimulation to QRS onset is a novel predictor of nonresponse to cardiac resynchronization therapy.

BACKGROUND: Left ventricular (LV) lead placement at the late activation site (LAS) has been proposed as an optimal LV pacing site (ie, Q-LV interval). However, LAS may be relevant to local electrical conduction, measured as an interval from LV pacing stimulation to QRS onset (S-QRS interval). OBJECTIVE: The purpose of this study was to evaluate the prognostic value of S-QRS for reverse remodeling and the impact of S-QRS on pacing QRS configuration in patients undergoing cardiac resynchronization therapy (CRT). METHODS: Sixty consecutive heart failure patients with a wide QRS complex underwent CRT. A site with Q-LV ≥95 ms was targeted for LV lead placement. A responder was defined as one with >15% reduction in LV end-systolic volume 6 months after CRT. RESULTS: LV lead placement with Q-LV ≥95 ms was achieved in 52 of 60 patients (86.7%). Thirty-two of 52 patients (61.5%) were responders. S-QRS was significantly shorter in responders than nonresponders (P <.01), whereas Q-LV was not significantly different. A cutoff value of 37 ms for S-QRS had sensitivity and specificity of 81% and 90%, respectively. Shorter S-QRS (<37 ms) showed significantly narrower LV pacing QRS width and biventricular pacing QRS width compared to longer S-QRS. After multivariate analysis, PQ interval (odds ratio 0.97; P = .01) and long S-QRS ≥ 37ms (odds ratio 0.014; P <.01) were independent predictors of response to CRT. CONCLUSION: In addition to a sufficient Q-LV, S-QRS can be a useful indicator of optimal LV lead position to achieve reverse remodeling. S-QRS contributes to the pacing QRS configuration associated with CRT response.

Prevalence, clinical characteristics, and outcome of atrial functional mitral regurgitation in hospitalized heart failure patients with atrial fibrillation.

BACKGROUND: Functional mitral regurgitation (MR) caused by reduced left ventricular ejection fraction (EF) and tethering, termed ventricular functional MR (VFMR), is associated with worse outcomes. Atrial functional MR (AFMR) caused by left atrial enlargement and annular dilatation was also recently described in patients with atrial fibrillation (AF). However, the clinical profiles of AFMR in hospitalized heart failure (HF) patients are unclear. We investigated the prevalence, clinical characteristics, and prognosis of AFMR in hospitalized HF patients with AF. METHODS: We analyzed 189 hospitalized HF patients with AF. The prevalence, clinical characteristics, and prognosis were compared between 4 groups: patients with EF ≥50% and no/mild MR (pEFnoMR), patients with EF <50% and no/mild MR (rEFnoMR), patients with EF ≥50% and moderate/severe MR (AFMR), and patients with EF <50% and moderate/severe MR (VFMR). RESULTS: The prevalence of AFMR was 15.9% in hospitalized HF patients with AF. AFMR patients were older and more likely to have an enlarged left atrium, lower tenting height, and moderate/severe tricuspid regurgitation than VFMR patients. There were no differences in all-cause death after discharge among pEFnoMR, rEFnoMR, and AFMR patients. AFMR patients were associated with a higher rate of a composite of cardiac death and readmission for HF compared with pEFnoMR and rEFnoMR patients (log-rank p=0.046 and p=0.004). There were no differences in composite endpoints between AFMR and VFMR patients (log-rank p=0.507). CONCLUSIONS: AFMR was present in a proportion of elderly hospitalized HF patients with AF, and was a condition requiring attention because of readmission for HF in a hospitalized HF cohort.

Heredity of flake- and stripe-variegated traits and their introduction into Japanese day-neutral winter-flowering sweet pea (Lathyrus odoratus L.) cultivars.

Sweet pea (Lathyrus odoratus L.) is a major cut flower in Japan, generally grown in greenhouses in winter to spring. The wild-type sweet pea is a long-day summer-flowering plant. The day-neutral winter-flowering ability, which allows cut-flower production in Japan, is a recessive phenotype that emerged by spontaneous mutation. Although Japanese winter-flowering cultivars and additionally spring-flowering cultivars, which have semi-long-day flowering ability generated by crossing the winter- and summer-flowering cultivars, have superior phenotypes for cut flowers, they have limited variation in color and fragrance. In particular, variegated phenotypes do not appear in modern winter- and spring-flowering cultivars, only in summer-flowering cultivars. We try to expand the phenotypic diversity of Japanese cut flower cultivars. In the processes, we introduced the variegated phenotypes by crossing with summer-flowering cultivars, and succeeded in breeding some excellent cultivars. During breeding, we analyzed the segregation ratios and revealed the heredity of the phenotypes. Here we review the heredity of these variegated phenotypes and winter-flowering phenotypes and their related genes. We also describe how we introduced the trait into winter-flowering cultivars, tracing their pedigrees to show both phenotypes and genotypes of the progeny at each generation. This knowledge is useful for the efficient breeding of new variegated cultivars.

Impact of diastolic dysfunction on the outcome of catheter ablation in patients with atrial fibrillation.

OBJECTIVE: To evaluate the impact of diastolic dysfunction on the outcome of atrial fibrillation (AF) ablation. METHODS: Eighty consecutive patients with drug-refractory symptomatic AF who underwent AF ablation were enrolled (65 males, 58 ± 10 years, 65 paroxysmal AF, 15 persistent AF). All patients underwent extensive pulmonary vein isolation with a double lasso technique using CARTO MERGE. Diastolic dysfunction was defined as a ratio of the mitral inflow early filling velocity to the velocity of the early medial mitral annular ascent of >10. The clinical and echocardiographic data were compared between the patients with and without diastolic dysfunction, and between the patients with and without AF recurrences after the AF ablation. RESULTS: Twenty-nine out of all the patients (36.3%) had diastolic dysfunction. Compared with the patients without diastolic dysfunction, the patients with diastolic dysfunction had higher brain natriuretic peptide (p=0.001) and C-reactive protein (p=0.023) levels, and a larger left atrial diameter (P=0.019). The AF-free rate after a single or repeat AF ablation procedure in the patients with diastolic dysfunction was lower than that in those without diastolic dysfunction (p=0.005 and p=0.013 by the log-rank test, respectively). In the univariate analysis, the patients with persistent AF and diastolic dysfunction were likely to have AF recurrences after a single AF ablation. The multivariate analysis indicated diastolic dysfunction as the only independent predictor of an AF recurrence after a single AF ablation (P=0.023). CONCLUSION: The patients with diastolic dysfunction had a worse outcome of the AF ablation not only for a single procedure but also a repeat procedure.

Time-dependent variation in coronary flow velocity reserve induced by adenosine triphosphate: comparison to low-dose dipyridamole.

BACKGROUND: Measuring the coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) has been widely performed using adenosine. Although adenosine infusion is known to induce transient variation of hyperemia, the timing to measure the CFVR has not been well addressed. Therefore, we aimed to clarify the difference between the peak CFVR and at 2 min following adenosine triphosphate (ATP) infusion compared to the CFVR after low-dose dipyridamole infusion. METHODS AND RESULTS: A total of 26 patients with coronary artery diseases underwent TTDE. The coronary flow velocity (CFV) of the left anterior descending artery (LAD) was monitored during ATP infusion at 0.14 mg/kg/min. The CFVR was measured both at the first peak and at 2 min following ATP infusion, and after dipyridamole infusion at 0.56 mg/kg/min for 4 min. The first peak of hyperemia occurred 63.7 ± 8 s after starting ATP infusion. The value of the peak CFVR was significantly higher than the CFVR at 2 min following ATP stress, which was equivalent to the CFVR after dipyridamole infusion (2.30 ± 0.92, 1.83 ± 0.77, and 1.70 ± 0.68, respectively, P < 0.001). Applying a cut-off value of 2.0 to predict angiographic LAD stenosis, the CFVR at 2 min following ATP stress was significantly correlated to the angiographic findings. However, the peak CFVR after ATP infusion did not correlate with the angiographic findings. CONCLUSIONS: During ATP infusion, the peak CFVR was significantly higher than the CFVR at 2 min, which was equivalent to the CFVR after low-dose dipyridamole. This finding should be considered for the standardization of CFVR measurements.