Cycle length of nonsustanied ventricular tachycardias among ICD patients: implications on subsequent appropriate therapies.

BACKGROUND: ICD patients with episodes of nonsustained ventricular tachycardias (NSVT) are at risk of appropriate therapies. However, the relationship between the cycle length (CL) of such NSVTs and the subsequent incidence of appropriate interventions is unknown. METHODS: 416 ICD patients with LVEF < 45% were studied. ICD programming was standardized. NSVT was defined as any VT of 5 or more beats at ≥ 150 bpm occurred in the first 6 months after implantation that terminated spontaneously and was not preceded by any appropriate therapy. The mean follow-up was 41 ± 27 months. RESULTS: We analyzed 2201 NSVTs (mean CL = 323 ms) that occurred in 250 patients; 111 of such episodes were fast (CL ≤ 300 ms). Secondary prevention (HR = 1.7; p < 0.001), number of NSVT episodes (HR = 1.05; 95% CI 1.04-1.07; p < 0.001) and beta-blocker treatment (HR = 0.7; p = 0.04) were independent predictors of appropriate interventions; however, the mean CL of NSVTs was not (p = 0.6). There was a correlation between the mean CL of NSVTs and the CL of the first monomorphic VT: r = 0.88; p < 0.001. This correlation was especially robust in individuals with > 5 NSVTs (r = 0.97; p < 0.001), with an agreement between both values greater than 95%. Patients with any fast NSVT experienced a higher incidence of VF episodes (26%) compared to those without NVSTs (3%) or with only slow NSVTs (7%); p < 0.001. CONCLUSIONS: Unlike the burden, the CL of NSVTs is not a predictor of subsequent appropriate interventions. However, there is a close relationship between the CL of NSVTs and that of arrhythmias that will later lead to appropriate therapies.

Fragmentation of the paced QRS complex: a marker of antitachycardia pacing effectiveness among ICD patients.

INTRODUCTION: The presence of notches in the paced QRS complex (P-QRS) from the right ventricular apex (RVA) reflects delays in the activation of the left ventricle and may therefore be associated with longer times of stimulus conduction. Our objective was to determine prospectively the relationship between the duration of a notch ≥0.1 mV in the P-QRS (DN) and the effectiveness of antitachycardia pacing (ATP). METHODS AND RESULTS: We followed 286 implantable cardioverter-defibrillator (ICD) patients with left ventricular dysfunction (pacing site: RVA) for 41 ± 27 months. ICD programming was standardized. P-QRS (100 bpm) was obtained at implant (50 mm/s). A total of 955 monomorphic ventricular tachycardias (VTs) with a cycle length of 335 ± 32 milliseconds occurred consecutively in 108 patients. ATP was successful in 84% of VTs. DN correlated with the probability of ineffective ATP (C = 0.67; P < 0.001), the cutoff point with the best sensitivity and specificity being 50 milliseconds. The adjusted mean ATP effectiveness per patient was 76% (95% CI: 72-85). Patients with a DN ≥ 50 milliseconds had a lower ATP efficiency: 67% (56-77) versus 92% (87-97) and a higher proportion of VTs terminated with shocks (SH): 31% (21-42) versus 8% (2-14); P < 0.001 for both. Although the occurrence of VT was similar (41% vs. 40%), the incidence of VT-related SH was higher in patients with a DN ≥ 50 (25% vs. 14%; P = 0.01) in the overall study population (n = 286). CONCLUSIONS: When ATP is applied to the RVA, a DN ≥ 50 milliseconds is associated with a lower ATP effectiveness and a higher risk of SH due to VT.

Timing of Ablation and Prognosis of Patients With Electrical Storm and Scar-Related Left Ventricular Dysfunction.

Although radiofrequency catheter ablation (RFCA) is indicated in electrical storm (ES) refractory to antiarrhythmic drugs, its most appropriate timing has not been determined. Our objective is to analyse the impact of the timing of RFCA on 30-day mortality in patients with ES and previous scar-related systolic dysfunction. In this multi-centre study, we analysed 104 patients (age: 72 ± 10, left ventricular ejection fraction: 30 ± 6%) attended consecutively due to an ES caused by monomorphic ventricular tachycardia. Sixty-four subjects were treated with RFCA (mean time from admission = 83 ± 67 hours) and 40 were not. Upon admission 25 (24%) individuals had severe heart failure. Mortality rate at 30 days was 24 (23%) patients. RFCA was associated with a reduction of 30-day mortality (hazard ratio = 0.2; p = 0.008). After showing a positive correlation between the time of the RFCA (hours) and survival at 30 days (C-statistic = 0.77; p <0.001), we found that only subjects ablated >48 hours after admission had lower mortality at 30 days than those treated conservatively: 38% (no RFCA) versus 30% (RFCA ≤48 hours) versus 7% (RFCA >48 hours) (adjusted hazard ratio for RFCA >48 hours vs others = 0.2; p = 0.007). Among the patients ablated, those who were non-inducible had lower 30-day mortality: 8% versus 29% (p = 0.03). Extracorporeal membrane oxygenation was associated with a higher rate of non-inducibility in RFCA >48 hours (100% vs 76%; p = 0.03), but not in RFCA ≤48 hours (60% vs 60%; p = 1). In conclusion, among high-risk patients with ES, RFCA performed >48 hours after admission is associated with a reduction in 30-day mortality. In such subjects, the probability of successful RFCA increases when performed under extracorporeal membrane oxygenation support.

Effectiveness of first versus successive antitachycardia pacing attempts: predictors and clinical consequences.

PURPOSE: Antitachycardia pacing (ATP) terminates the majority (but not all) of slow ventricular tachycardias (S-VT) with a cycle length (CL) > 320 ms. Usually, several ATP therapies are programmed in the S-VT zone. Our objective is to analyse the ATP effectiveness, comparing the first ATP attempt (ATP-1) to the second (ATP-2) and third (ATP-3) attempts. METHODS: We studied 556 S-VT (CL = 354 ± 18). ATP programming was standardized and included three bursts of 15 pulses at 91% of VT CL. RESULTS: ATP effectiveness declined from ATP-1 (436/556: 78%) compared to ATP-2 (24/103: 23%) and ATP-3 (10/79: 13%) (p < 0.01) for all comparisons. The percentage of variation of RR intervals (P-RR, %) was higher prior to effective ATP-1 (2.73 ± 1.45 vs. 1.23 ± 0.9; p < 0.001). After an ineffective ATP-1, the P-RR decreased dramatically, with no differences between episodes terminated or not at ATP-2 (0.6 ± 0.14 vs. 0.44 ± 0.16; p = 0.6) or ATP-3 (0.54 ± 0.15 vs. 0.52 ± 0.14; p = 0.7). The post-pacing interval-CL difference (PPI-TCLd) after an unsuccessful ATP-1 was shorter in episodes terminating at ATP-2 or ATP-3 (180 ± 24 vs. 211 ± 15 ms; p < 0.001). Several independent predictors of ATP efficacy were found, as follows: (a) ATP-1: P-RR, % (OR = 7.3; p < 0.001), beta-blockers (OR = 4.1; p < 0.001) and QRS ≥ 120 ms (OR = 0.3; p < 0.001); (b) ATP-2: PPI-TCLd, ms (OR = 0.94; p = 0.001) and QRS ≥ 120 ms (OR = 0.6; p = 0.04); (c) ATP-3: PPI-TCLd, ms (OR = 0.93; p = 0.009). CONCLUSIONS: The effectiveness of ATP is mainly due to ATP-1. The regularization of RR intervals after ineffective ATP-1 underlies the lower efficacy of successive attempts. Shorter PPI-TCLd is associated with higher effectiveness of ATP-2 and ATP-3. Since a duration of QRS ≥ 120 ms predicts a longer PPI-TCLd, patients with wide QRS complexes have less effective ATP-2 and APT-3.

Beta-blocker therapy is associated with a lower incidence of syncope due to fast ventricular tachycardias among implantable cardioverter-defibrillator patients with left ventricular dysfunction: results from a multicenter study.

INTRODUCTION: Among implantable cardioverter-defibrillator (ICD) patients, a substantial proportion of syncopes are due to fast ventricular tachycardias (FVTs). In the experimental models of ventricular tachycardias, the arterial vasoconstriction plays an important role in recovering the arterial pressure. Since beta-blockers increase vascular resistance, we hypothesized that beta-blockers could reduce the occurrence of syncope due to FVTs. Our objective was to determine the relationship between the beta-blocker therapy and the incidence of syncope in FVT (cycle length [CL] 250-320 ms) occurring in ICD patients. Slow VTs were excluded because of the lack of symptoms and VF episodes because of the small number. METHODS AND RESULTS: In this multicenter study, 226 patients (LVEF 31 ± 10%) with single-chamber ICDs were followed. FVT programming was standardized, including antitachycardia pacing (ATP) as initial therapy. Symptoms were correlated with ICD-stored episode data of FVTs. The beta-blocker therapy was determined at each FVT presentation. We analyzed 289 FVTs (CL 291 ± 21 ms; 77% under beta-blockers; median of the duration:8 s) occurring consecutively in 52 ICD patients. The frequency of FVT-related syncope was 22 (7.6%). Beta-blockers were associated with a lower heart rate preceding FVT (85 ± 22 vs. 94 ± 23 bpm; p = 0.009), a higher ATP effectiveness (86 vs. 57%; p < 0.001), a lower duration of episodes (8 [2] vs. 10 [14] s; p < 0.001), and a lower incidence of FVT-related syncope (4.5 vs. 18%; p < 0.001). By logistic regression, a FVT > 8 s (OR = 21; p = 0.003) and the beta-blocker therapy (OR = 0.3; p = 0.012) were found as independent predictors of syncope. CONCLUSION: Among ICD patients with left ventricular dysfunction, beta-blockers are associated with a lower incidence of FVT-related syncope.

Prognostic Significance of Nonsustained Ventricular Tachycardia Episodes Occurring Early After Implantable Cardioverter-Defibrillator Implantation Among Patients With Left Ventricular Dysfunction.

Nonsustained ventricular tachycardias (NSVTs) are frequently observed in patients with left ventricular (LV) dysfunction. The prognostic implications of such NSVTs are conflicting. Our objective was to determine the relation between the burden of NSVT occurring early (within the first 6 months after ICD implant) and prognosis among ICD patients with LV dysfunction. We followed 416 ICD patients (age: 65 ± 11 years; LV ejection fraction: 30 ± 8; ischemic origin: 62%; primary prevention: 63%) with LV dysfunction for 41 ± 27 months. ICD programming was standardized. NSVT was defined as any VT of ≥5 beats at ≥150 beats/min which did not meet the detection criteria occurring within the first 6 months after ICD implant. A total of 250 patients (60%) presented at least one NSVT (median = 2; interquartile range 0 to 7). We classified the patients into 3 groups according to the number of NSVTs: no NSVT (n = 166); 1 to 5 NSVTs (n = 130); and >5 NSVTs (n = 120). The incidence of cardiac mortality (7.2% vs 17.7% vs 31.7%; p = 0.003), hospitalizations for heart failure (10.6% vs 24.4% vs 44.7%; p <0.001), and appropriate shock (15.7% vs 24.8% vs 43.8%; p <0.001) increased significantly with the number of NSVTs. By multivariate analysis, >5 NSVTs were found to be an independent predictor of cardiac mortality (hazard ratio [HR] 1.75; p = 0.03), hospitalization due to heart failure (HR 1.72; p = 0.001), and appropriate shock (HR 1.89; p <0.001) but not of inappropriate therapy (HR 0.9; p = 0.6). In conclusion, among ICD patients with LV dysfunction, NSVT episodes occurring in the first 6 months after implant are independently associated with a poor prognosis. Subjects with >5 NSVTs are at the highest risk.

Office-based sclerotherapy for recurrent epistaxis due to hereditary hemorrhagic telangiectasia: a pilot study.

BACKGROUND: The aim of this pilot study is to evaluate office-based sclerotherapy using sodium tetradecyl sulfate (STS) for epistaxis due to hereditary hemorrhagic telangiectasias (HHT). Patients with HHT suffer from unpredictable, recurrent, severe nasal bleeding necessitating emergency care, nasal packing, blood transfusions, and invasive procedures. METHODS: In this retrospective study 7 patients with a history of treatment for recurrent epistaxis due to HHT were treated in an office-based setting with intralesional injection of STS. Treatment results were evaluated using a questionnaire. All patients had undergone multiple prior procedures attempting to control epistaxis. RESULTS: Patients had an average of 5 sclerotherapy treatments for HHT. Patients were treated using topical and/or local anesthesia with no reports of discomfort. Bleeding requiring intervention did not occur during the procedures. After the procedure all patients (100%) reported significantly less frequent and less severe nasal bleeding. A total of 83% reported that their need for nasal packing was reduced. All patients were willing to undergo the same treatment again. No complications such as perforation, crusting, or foul smell were reported. CONCLUSION: This is the first clinical experience demonstrating that office-based sclerotherapy with STS is a safe, tolerable, and useful alternative for the treatment of epistaxis due to HHT.

El ruido como problema higiénico en microdistritos de La Habana: parte II; proyección en la comunidad / The noise as hygienic problem in microdistrits of Havana: part II; projection in the community

Fue estudiada la conciencia de sí y del entorno, la personalidad y el grado de alteraciones psíquicas y neurovegetativas en una muestra de 400 amas de casas residentes en cuatro microdistritos contrastados por la naturaleza del ruido en la ciudad de La Habana entre 1984 y 1985. El ruido de la zona comercial se asoció con mayor molestia y grado de trastornos y resultó congruente con su más alto nivel sonoro. Aunque el ruido industrial sigue en importancia en nivel sonoro, en esta área se encontraron la menor molestia y los mínimos trtastornos de salud, acompañados de un efecto de habituación y deterioro de la conciencia y la comunicación con el medio. En la zona residencial, de mínimo nivel sonoro, aparece un elevado grado de exigencia de condiciones favorables del entorno, y la zona aledaña al aeropuerto resultó una transición entre las características de las zonas industrial y residencial