Single-chamber ventricular pacing increases markers of left ventricular dysfunction compared with dual-chamber pacing.

AIMS: Large randomized trials comparing DDD with VVI pacing have shown no differences in mortality, but conflicting evidence exists in regard to heart failure endpoints. Here we evaluated the effect of pacing mode on serum levels of brain natriuretic peptide (BNP) and amino-terminal-proBNP (NT-proBNP). Methods Forty-one patients (age 73 +/- 10 years) with dual-chamber pacemakers were included in a prospective, single-blind, randomized crossover study evaluating the impact of DDD(R)/VDD versus VVI(R) mode on objective and functional parameters. Data were collected after a 2-week run-in phase and after 2 weeks each of VVI(R) and DDD(R)/VDD pacing or vice versa. Results BNP and NT-proBNP levels during DDD(R)/VDD stimulation (151 +/- 131 and 547 +/- 598 pg/mL) showed no change compared with baseline (154 +/- 130 and 565 +/- 555 pg/mL), but a significant 2.4-fold increase was observed during VVI(R) mode [360 +/- 221 and 1298 +/- 1032 pg/mL; P < 0.001 compared with DDD(R)/VDD]. The assessment of functional class, the presence of pacemaker syndrome [49% in VVI(R) mode] and the patients' preferred pacing mode showed significant differences in favour of DDD(R)/VDD pacing. CONCLUSION: Patients can differentiate between DDD(R)/VDD and VVI(R) pacing, and prefer the former. Compared with DDD(R)/VDD pacing, VVI(R) stimulation induces a two- to three-fold increase in serum BNP and NT-proBNP levels.

Admission glucose concentrations independently predict early and late mortality in patients with acute myocardial infarction treated by primary or rescue percutaneous coronary intervention.

BACKGROUND: In patients with acute myocardial infarction (MI), increased plasma glucose levels at hospital admission are associated with worse outcome. We aimed to assess the predictive value of admission glucose concentrations on short- and long-term mortality in patients with acute MI undergoing primary or rescue percutaneous coronary intervention (PCI). METHODS: We analyzed the 30-day and long-term (mean follow-up 3.7 years) outcome of 978 patients prospectively included in a single-center registry of patients with acute MI treated with PCI within 24 hours after onset of symptoms. Patients were classified according to plasma glucose levels at admission: < 7.8 mmol/L (group I, n = 322), 7.8 to 11 mmol/L (group II, n = 348), and > 11.0 mmol/L (group III, n = 308). RESULTS: Mortality at 30 days was 1.2% in group I, 6.3% in group II, and 16.6% in group III (P < .001). After multivariate adjustment for age, the presence of cardiogenic shock, and TIMI 3 flow after PCI, the association of mortality with glucose classification remained significant (P value for trend = .003). The relative risk of death at 30 days for group III versus group I was 3.9 (95% CI 1.2-13.2). During long-term follow-up, mortality was similar in groups I and II. However, in group III adjusted mortality remained significantly increased compared with group I (relative risk 1.76, CI 1.01-3.08). CONCLUSIONS: In patients undergoing emergency PCI for acute MI, glucose levels at hospital admission are predictive for short- and long-term survival. Knowledge of admission glucose levels may improve initial bedside risk stratification.