Biomedical subjects

Pier Antonio Ravazzi

Publications and source records attributed to Pier Antonio Ravazzi.

4 recordsLinked to original sources

PubMed2006

Comparison of 1-year effects of left ventricular and biventricular pacing in patients with heart failure who have ventricular arrhythmias and left bundle-branch block: the Bi vs Left Ventricular Pacing: an International Pilot Evaluation on Heart Failure Patients with Ventricular Arrhythmias (BELIEVE) multicenter prospective randomized pilot study.

BACKGROUND: Little is known on the chronic effects of left ventricular pacing (LV) in heart failure. METHODS: Seventy-four patients with LBBB, QRS >130 milliseconds, New York Heart Association class (Bradley DJ, Bradley EA, Braughman KL, et al. Cardiac resynchronization and death from progressive heart failure: a meta-analysis of randomized controlled trials. JAMA 2003;289:730-40.) II, LV ejection fraction (LVEF) <35%, and a class I cardioverter/defibrillator indication were implanted with CRT-D devices and were randomized to either LV or biventricular (BiV) pacing. Response (defined as increases of >5 points increase of LVEF and/or > or = 10% 6-minute walking test [6MWT]) between LV and BiV pacing were compared in an attempt to define the number of patients needed to claim noninferiority of LV pacing. In addition, absolute change in LVEF at 12 months in heart failure patients treated with LV pacing was evaluated. The safety of LV pacing was assessed comparing the total number of ventricular arrhythmia episodes, of hospitalizations, and of deaths between the two pacing modes. RESULTS: The percentage of responders was comparable for both groups (LV = 75%, BiV = 70%, P = .788); based on the 95% CI of the difference between the groups, 1100 patients would be needed to claim noninferiority of LV pacing (with a 5% CI lower limit). LV pacing induced siginificant LVEF increase (5.2%, P = .002). These results remained unchanged after performing adjustment analyses. There were no differences in the numbers of ventricular arrhythmias, hospitalizations, and death events between the 2 pacing modes. CONCLUSIONS: At 12 months, percentage of responders to LV pacing was similar to BIV pacing. Furthermore, LV pacing achieved a significant increase of ejection fraction. LV pacing is both safe and feasible.

Aged↗

PubMed2005

An algorithm for verifying biventricular capture based on evoked-response morphology.

Cardiac resynchronization therapy relies on consistent beat-by-beat myocardial capture in both ventricles. A pacemaker ensuring right (RV) and left ventricular (LV) capture through reliable capture verification and automatic output adjustment would contribute to patients' safety and quality of life. We studied the feasibility of an algorithm based on evoked-response (ER) morphology for capture verification in both the ventricles. RV and LV ER signals were recorded in 20 patients (mean age 72.5 years, range 64.3-80.4 years, 4 females and 16 males) during implantation of biventricular (BiV) pacing systems. Leads of several manufacturers were tested. Pacing and intracardiac electrogram (IEGM) recording were performed using an external pulse generator. IEGM and surface-lead electrocardiogram (ECG) signals were recorded under different pacing conditions for 10 seconds each: RV pacing only, LV pacing only, and BiV pacing with several interventricular delays. Based on morphology characteristics, ERs were classified manually for capture and failure to capture, and the validity of the classification was assessed by reference to the ECG. A total of 3,401 LV- and 3,345 RV-paced events were examined. In the RV and LV, the sensitivities of the algorithm were 95.6% and 96.1% in the RV and LV, respectively, and the corresponding specificities were 91.4% and 95.2%, respectively. The lower sensitivity in the RV was attributed to signal blanking in both channels during BiV pacing with a nonzero interventricular delay. The analysis revealed that the algorithm for identifying capture and failure to capture based on the ER-signal morphology was safe and effective in each ventricle with all leads tested in the study.

Aged↗

PubMed2003

Cardiac resynchronization and implantable cardioverter defibrillator therapy: preliminary results from the InSync Implantable Cardioverter Defibrillator Italian Registry.

The aim of this study was to evaluate ventricular arrhythmias occurring in recipients of the InSync ICD for the primary and secondary prevention of sudden death. The InSync ICD was implanted in 142 patients (128 men; mean age 65 +/- 10 years) with heart failure (mean NYHA functional Class 3.0 +/- 0.7) and wide QRS (mean 159 +/- 33 ms). The underlying etiology was ischemic in 55%, idiopathic in 33%, and valvular or hypertensive cardiomyopathy in 12% of patients. The numbers of arrhythmic episodes/100 patient-months was computed with their 95% CI, assuming a Poisson distribution. Implants were performed in 48 (34%) patients who did not have an ACC/AHA guidelines Class I indication for ICD therapy. A total of 104 patients were compliant for follow-up visits. During a 9-month median (range 0.1-24) follow-up of 104 compliant patients, 19 experienced a total of 94 ventricular arrhythmias, all successfully interrupted or self-terminated, with a median number of two separate episodes, corresponding to a rate of 10 episodes/100 person-month (95% CI 8-12). A rate of 12 episodes/100 person-months (95% CI 10-15) was measured in the subgroup of patients with ACC/AHA class I indications, versus two episodes/100 person-months (95% CI 1-5) in the remainder of the population. Among 12 deaths, 9 were due to heart failure, 1 to a non-cardiovascular cause, and 2 to unknown causes. The implantation of ICD in heart failure patients has been prominently extended to primary prevention. Patients without standard ICD indications experienced life-threatening arrhythmic events. The impact of ICD combined with cardiac resynchronization therapy on arrhythmic profile, mortality, and costs in this subgroup of patients need to be more precisely studied, with a particular focus on the various types of underlying heart disease.

Adult↗

PubMed2002

[Role and interactions of the cardiologist in a regional institutional project of primary prevention].

BACKGROUND: Evidence is available in support of the policies for a population-wide approach to shifting risk factor distribution; on the other side, setting up enduring projects of primary prevention is difficult, as well as gathering the right experts. METHODS: In 1999 the Piedmont Region's Administration set up a multi-year intervention with the aim at reducing risk factors and increasing protective factors of oncologic and cardiovascular diseases in the general population, particularly in disadvantage groups. The cardiologists played a primary role by supporting the project of evidence-based guidelines, producing bibliographic reviews and spreading coronary risk maps. A main group of trainers was set up in each Local Health Service to promote a system of counseling lifestyles, with the central reference of the general practitioner activity. As a second step, a mass-media campaign has been set up using health advertisements on newspapers, television, public transports, notice-boards on the following subjects: nutrition, hypertension, tobacco, physical activity, stress; warehouses, food markets, trains and squares were involved. Moreover, a newsletter review has been published since January 2000, to produce basic models, most effective interventions and recommendations for their implementation. RESULTS: A new care for the primary prevention and counseling arguments as well as the need for continuous training to promote preventive actions were shown to general practitioners. A system to identify the best channels, communication ways and the most effective messages for healthy lifestyles was settled. A model of monitoring risk factor changes and protective behaviors in the population, describing social differences, was established to better plan and assess effective interventions. CONCLUSIONS: After more than half a century of productive public health science, there is an urgent need that Government Administrations steer their health policies towards determinants of health and create the best conditions to make citizens to improve their lifestyle.

Cardiology↗