Clinical implications of nonsarcomeric gene polymorphisms in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is characterized by cardiomyocyte hypertrophy and fibrosis. Although is an autosomal dominant trait, a group of nonsarcomeric genes have been postulated as modifiers of the phenotypic heterogeneity. MATERIAL AND METHODS: We prospectively recruited 168 HCM patients and 136 healthy controls from three referral centres. Patients and controls were clinically stable at entry in the study. Nine polymorphisms previously associated with ventricular remodelling were determined: I/D ACE, AGTR1(A1666C), CYP11B2(C344T), PGC1-α(G482S), COLIA1(G2046T), ADRB1(R389G), NOS3(G894T), RETN(-420C>G) and CALM3(-34T>A). Their potential influence on prognosis, assessed by hospital admissions, and their cause were recorded. RESULTS: The median follow-up time was 49·5 months. Allele and genotype frequencies did not differ between patients and controls. Thirty-six patients (21·5%) required urgent hospitalization (18·5% for heart failure, 22·2% for atrial arrhythmias, 11·1% for ventricular arrhythmias, 29·6% for ischaemic heart disease, 14·8% for stroke and 3·7% for other reasons) with a hospitalization rate of 8·75% per year. Multivariate analysis showed an independent predictive value for noncarriers of polymorphic COL1A1 allele [HR: 2·76(1·26-6·05), P = 0·011] and a trend in homozygous carriers of ADRB1 Arg389 variant [HR: 1·98(0·99-4·02); P = 0·057]. CONCLUSION: Our study suggests that COL1A1 polymorphism (2046G>T) is an independent predictor of prognosis in HCM patients supporting the importance of nonsarcomeric genes on clinical prognosis in HCM.

Selecting the best site for pacing leads after cardiac surgery by evaluating the asynchrony of myocardial deformation observed with different pacing sites.

INTRODUCTION AND OBJECTIVES: After cardiac surgery, temporary pacing leads are routinely implanted in the right ventricle (RV). The objective was to investigate the effect of different ventricular pacing locations on cardiac synchrony (by evaluating myocardial deformation, or strain) and efficiency in patients undergoing cardiac surgery. METHODS: Interventricular asynchrony (i.e. the difference in the time of onset of deformation between right and left ventricles; Tε-R/L) and intraventricular asynchrony (i.e. the standard deviation and maximum difference in the time of onset of deformation in six segments of the left ventricle [LV]; Tε-SD and Tε-MD, respectively) were assessed in 19 patients. Doppler echocardiography was used to evaluate these parameters and cardiac output after pacing in the RV and in three different LV segments. RESULTS: Pacing in the RV resulted in the greatest increases in asynchrony parameters from baseline: Tε-R/L 59.8 ms (standard deviation [SD] 40.5 ms) vs. 28.23 ms (SD 56.9 ms), P=.002; Tε-SD 53.2 ms (SD 34.4 ms) vs. 36.6 ms (SD 34.9 ms), P=.007; and Tε-MD 135.3 ms (SD 82.9 ms) vs. 90.5 ms (SD 87.4 ms), P=.007. Pacing in the LV resulted in less asynchrony: for anterior LV pacing, Tε-R/L was 17.2 ms (SD 53.8 ms), Tε-SD was 35.8 ms (SD 17.9 ms), and Tε-MD was 91.3 ms (SD 45.2). The change from baseline was not significant. Cardiac output was lower after RV pacing than after anterior LV pacing: 4.36 (SD 1) vs. 4.70 (SD 1); P=.001. CONCLUSIONS: Pacing in the LV produced less asynchrony than RV pacing. In addition, anterior LV pacing resulted in a higher cardiac output than RV pacing. These findings suggest that the location normally used for temporary leads after cardiac surgery should be changed.

[Multiple pulmonary nodules and amiodarone. KL-6 as a new diagnostic tool]. / Nódulos pulmonares múltiples y amiodarona. KL-6 como nueva herramienta diagnóstica.

Pulmonary toxicity is an infrequent but serious adverse event in patients treated with amiodarone. The main problem at present is that we lack the necessary tools to detect this event or predict which patients will develop pulmonary toxicity. Serum Krebs von den Lungen-6 (KL-6) has been previously recognized as a marker for the activity of diffuse interstitial lung disease. We describe a patient with pulmonary toxicity due to amiodarone with increased blood levels of this new marker, and discuss the clinical usefulness of this new diagnostic tool.

[Ablation of the cavotricuspid isthmus. Randomized prospective study of radiofrequency ablation with irrigated catheters versus standard catheters]. / Ablación del istmo cavotricuspídeo. Estudio prospectivo aleatorizado sobre ablación mediante radiofrecuencia con catéteres irrigados frente a catéteres estándar.

INTRODUCTION AND OBJECTIVES: An important limitation of the ablation with standard catheter is the volume and limited depth of the lesions created. The irrigated catheters, due to a larger and deeper lesion could be useful in patients with typical atrial flutter. The aim of this study was to prospectively compare the ablation procedure with an irrigated-tip catheter versus the standard catheter in this group of patients. METHODS: A total of 37 consecutive patients referred to ablation of the cavotricuspid isthmus for typical atrial flutter were randomized either to be performed by an standard catheter (20 patients with mean age of 62 18 years, 18 males) or an irrigated-tip catheter (17 patients with mean age 71 4 years, 13 males). RESULTS: With standard catheters, complete ablation of the cavotricuspid isthmus was achieved in 18 patients (90%). With a mean of 19 15 applications. With the irrigated-tip catheters the complete ablation of the isthmus was achieved with a mean of 8 7 applications (p < 0.001). Both mean duration of the procedure (164 56 versus 70 35 minutes) and fluoroscopic time (40 16 versus 16 8 minutes) was significantly less with irrigated catheters (p < 0.001). There were no significant clinical complications during the procedure nor later on. No patient presented ischemic symptoms nor alterations on the ST segment. CONCLUSIONS: The employment of irrigated-tip catheters achieved a high success rate with safety shortening the procedure time and radiation exposure.