Biomedical subjects

Jesus Almendral

Publications and source records attributed to Jesus Almendral.

5 recordsLinked to original sources

PubMed2006

Relation of heart rate turbulence to severity of heart failure.

The aim of this study was to evaluate the association between heart rate turbulence (HRT) parameters and clinical, biochemical, echocardiographic, and electrocardiographic measures of heart failure (HF) in a large, prospectively enrolled population of patients with HF to determine whether HRT could be considered a marker of HF advancement and progression, giving insight into hemodynamic changes as well as changes of the autonomic nervous system. In 487 patients with HF (mean age 63 years), the following tests were performed: 12-lead surface electrocardiography, echocardiography, chest x-rays, N-terminal-pro-brain natriuretic peptide levels, and 24-hour Holter monitoring for HRT and heart rate variability analyses. Most patients were in New York Heart Association class II (82%) and had a mean left ventricular (LV) ejection fraction of 37 +/- 14%. Both HRT parameters, but especially turbulence slope, were significantly correlated with clinical indexes of HF (the third heart sound, peripheral edemas, jugular distension, and pulmonary congestion). Patients in New York Heart Association class III had significantly lower turbulence slopes and greater turbulence onset values than those in class II. Significant correlations were found between HRT parameters and the LV ejection fraction as well as with LV diameters. HRT parameters were significantly correlated with N-terminal-pro-brain natriuretic peptide levels (r = -0.47, p <0.001 for turbulence slope). Multivariate analyses showed that abnormal HRT parameters were independent predictors of HF severity measured by New York Heart Association class III and a LV ejection fraction <40%. In conclusion, the findings indicate that in patients with HF, HRT reflects well the severity of HF and associated LV dysfunction, which were verified in this study by a series of established clinical, echocardiographic, and biochemical parameters.

Adolescent↗

PubMed2004

Predictors of in-hospital ventricular fibrillation or torsades de pointes in patients with acute symptomatic bradycardia.

Severe bradyarrythmias remain as an important cause for hospital urgent admission and these patients can suffer potentially lethal complications (such as ventricular fibrillation [VF] and torsades de pointes [TdP]) between hospital admission and final therapy. Incidence and predictors of these tachyarrhythmias have not been well established. We retrospectively studied all consecutive patients (N = 243, age 75 +/- 10 years; 47% men) admitted to the emergency department of a general hospital between January 1998 and July 2000 for symptomatic bradyarrhythmia. Concomitant therapy included diuretics (25%), digitalis (10%), beta-blockers (10%), amiodarone (2%), and verapamil or diltiazem (8%). Syncope was the most frequent symptom at admission (54%). The most prevalent inclusion bradyarrhythmia was > or =second-degree AV block (82%). Eleven patients (4.5%) presented VF or TdP. Univariate predictors for these complications were previous amiodarone or diuretic intake, presentation as syncope, low serum potassium level, and longer QTc at admission. Multivariate analysis with logistic regression showed only therapy with diuretics and/or amiodarone and QTc at admission as significant predictors for TdP or VF development. Incidence of VF or TdP in patients admitted for symptomatic bradyarrhythmia is relatively important. A prolonged QTc interval and/or therapy with amiodarone or diuretics can predict their presentation.

Adult↗

PubMed2004

Basic assessment of paced activation sequence mapping: implications for practical use.

Some experiences support the use of atrial paced activation sequence mapping, but there is no systematic study assessing its spatial resolution, reproducibility, and influence of pacing parameters. The aim of this study was to evaluate these issues by using a 24-pole catheter positioned at the atrial aspect of the tricuspid and mitral annuli in 15 patients. Bipolar pacing was performed at two sites (right and left atria), 2 cycle lengths (300 and 500 ms) and two outputs (twice and tenfold the late diastolic threshold voltage for 2-ms pulses). The elapsed time between the atrial activation at the two dipoles adjacent to the pacing dipole (activation time [AT]) was measured during each pacing sequence. Changes in cycle length did not modify the AT. The increase in voltage slightly modified the AT (maximum -2 ms at the RA; 95% CI -3 to -1 ms) due to a greater shortening of the conduction time to the dipole located next to the anode. The 95% limits of the intraobserver and interobserver agreements in the AT measurement were -2 to 3 ms and -3 to 3 ms, respectively. The spatial resolution was studied in ten patients by measuring the AT during pacing from each dipole of a 20-pole catheter with a 1-3-1 mm interelectrode distance. The mean AT change was 10 +/- 4 ms per 6 mm of pacing site displacement (95% CI 8-11 ms, range 2.5-20 ms). In conclusion, paced atrial activation sequence analysis is reproducible, accurate, and relatively independent of pacing parameters.

Cardiac Pacing, Artificial↗

PubMed2003

Ablation of electrograms with an isolated, delayed component as treatment of unmappable monomorphic ventricular tachycardias in patients with structural heart disease.

OBJECTIVES: We sought to evaluate the feasibility of identifying and ablating the substrate of unmappable ventricular tachycardia (VT). BACKGROUND: Noninducible and nonstable VT cannot be ablated by the conventional approach. METHODS: We studied 24 patients with documented monomorphic VT. Twenty-one patients had ischemic cardiomyopathy, two had nonischemic cardiomyopathy, and one had tetralogy of Fallot. Twelve patients had an implantable cardioverter-defibrillator. Conventional activation mapping was not possible in 18 patients: at least 1 of the clinical VTs or the clinical VT was not inducible in 12 patients, and VT was not tolerated in 6 patients. This group had experienced between 1 and 106 VT episodes in the month before the ablation procedure. Endocardial electroanatomic activation maps (Carto System) during sinus rhythm (SR) and right ventricular apex (RVA) pacing were obtained to define areas for which an electrogram displayed isolated, delayed components (E-IDC). These electrograms were characterized by double or multiple components separated by >/=50 ms. RESULTS: One area of E-IDC was recorded in 20 patients, and 2 or more were recorded in 4 patients. In 23 patients, these areas were detected during RVA pacing; in only 14 during SR. An E-IDC area related to the clinical VT was identified in each patient. Ablation guided by E-IDC suppressed all but one clinical VT whose inducibility suppression was tested. During a follow-up period of 9 +/- 4 months, three patients had recurrences of the ablated VT and two of a different VT. CONCLUSIONS: Electrograms with IDCs related to clinical VT can be identified in the majority of patients during RVA pacing. Radiofrequency ablation of E-IDC seems effective in controlling unmappable VT.

Adult↗

PubMed2003

Systolic dysfunction is a predictor of long term mortality in men but not in women with heart failure.

AIMS: To evaluate possible gender differences in clinical profile and outcome of patients hospitalised with heart failure. METHODS AND RESULTS: During 1996 a total of 1065 hospital in-patients had confirmed heart failure, with follow-up data through 2002. Women (58%) were significantly older, had higher prevalence of hypertension and diabetes, and lower prevalence of ischaemic heart disease, chronic pulmonary disease and alcoholism. The proportion of patients with normal left ventricular ejection fraction (LVEF) increased with age, but in all age groups women had normal LVEF more frequently than men. Echocardiography was performed less frequently in females: 62% vs. 71% in men, P<0.01, and this finding was consistent in all age groups. During follow-up (median 19 months) 507 patients died (216 men [48.8%] and 291 women [46.8%]). Gender was not a predictor of survival when LVEF was included in the model (RH Male Gender 0.8, 95% CI 0.6 to 1.1, P=0.2). There was a significant interaction gender-LVEF (P=0.048): survival was similar in both genders with LVEF >0.3 but women with LVEF </=0.3 had a better prognosis than their male counterparts. CONCLUSIONS: Survival is similar in women irrespective of LVEF and in men with LVEF >0.3 while men with severely depressed LVEF have a worse prognosis.

Adolescent↗