Correlation of myocardial interstitial collagen in the right ventricular septum with ventricular function of patients with ischemic cardiomyopathy

BACKGROUND

Myocardial collagen content influences ventricular relaxation, contraction, and morphology. Its relationship with ventricular function in patients (Pts) with ischemic cardiomyopathy (ICMP) has not yet been fully studied in humans.

OBJECTIVE

To assess the relationship between interstitial collagen content in non-infarcted areas of the right ventricular septum and ventricular function in ICMP.

METHODS

31 pts with coronary artery disease were divided into four groups as follows:The control group consisted of 7 pts with normal left (LVEF) and right (RVEF) ventricular ejection fraction (group C); Group 1: 5 patients with RVEF < 40%; Group 2: 9 pts with LVEF < 40%; and Group 3, 10 pts with biventricular dysfunction. RVEF and LVEF were measured by radionuclide angiography. For quantitative analysis of interstitial collagen volume fraction (CVF), endomyocardial biopsy specimens were taken from the right ventricle and stained with picrosirius red.

RESULTS

Mean CVF was significantly higher in group 3, compared with the control group and with groups 1 and 2 (30.2 +/- 7.9% vs. 6.8 +/- 3.3% vs. 15.8 +/- 4.1% vs. 17.5+/-7.7%, respectively; p =0.0001). It was also significantly higher in patients belonging to group 2, compared with those in the control group (17.5 +/- 7.7% vs. 6.8 +/- 3.3%, p =0.0001). CVF was inversely correlated with RVEF (r = - 0.50, p = 0.003) and LVEF (r = -0.70, p = 0.0001).

CONCLUSION

In ICMP, CVF is elevated in non-infarcted areas of the right ventricular septum and inversely correlated with right and left ventricular function.

Adult extracorporeal life support: a failed or forgotten concept?

BACKGROUND

The extracorporeal membrane oxygenation (ECMO) has been used in the neonatal and childhood periods with excellent results. The adult experience has been modest with inferior immediate results. The intermediate survival, however, has been promising. We have been using the extracorporeal membrane oxygenation for temporary mechanical circulatory support of adults that present with acute refractory cardiogenic shock in our institution. There is no other published experience of the use of this system in this scenario in Brazil.

OBJECTIVE

To describe our experience with the use of the extracorporeal membrane oxygenation for circulatory support in adults.

METHODS

Retrospective analysis of the medical files of patients submitted to the implant of extracorporeal membrane oxygenation system for circulatory assistance in acute and refractory cardiogenic shock.

RESULTS

Eleven patients (63,5 yo; 45,5% male) were considered for analysis from 2005 to 2007. Median support time was 77 hours (10-240 h) and 5 patients have survived 30 days (45,5%). Two patients were subsequently submitted to prolonged paracorporeal circulatory assistance. Mortality on ECMO (6 patients) was due to multiple organ failure (66,6%) and refractory bleeding (33,4%).

CONCLUSION

ECMO system is an option to be used in acute refractory cardiogenic shock as a bridge to recovery or selecting patients that might benefit from prolonged paracorporeal assist devices (bridge to bridge).

[Prognostic value of the Six-Minute Walk Test in heart failure]

OBJECTIVE

This study aimed to assess the true usefulness of the Six-Minute Walk Test as a prognostic indicator and its contribution to clinical practice with heart failure patients.

METHODS

In order to investigate the actual value of the Six-Minute Walk Test as an objective measure of mortality probability in patients with heart failure, the test was applied to 179 stable patients (120 men and 59 women, mean age 58.32 +/- 12.7 years, with NYHA class II and III heart failure and an ejection fraction (LVEF) of 34.91 +/- 12.4%). Patients were instructed to walk for 6 minutes and then, four hours later, underwent a conventional exercise stress test (as per Naughton Protocol). Patients were followed for an average of eighteen months.

RESULTS

The average distance walked was 521.11 +/- 76.1 meters. During the follow-up period, 66 patients (36.9%) died. There was a significant correlation between the distance walked during the test and mortality (p < 0.0001). The logistic regression model identified the distance walked during the test as the most important independent predictor of mortality (p = 0.0001). A distance shorter than 520 meters identified the patients with an increased probability of death. There was a significant correlation between the number of metabolic equivalents (METs) measured during the conventional exercise stress testing and mortality rate (p = 0.0001).

CONCLUSION

The Six-Minute Walk test is a simple, safe and powerful method to assess the prognosis of patients with NYHA class II and III heart failure. It is an objective examination that may replace the conventional ergometric test for the prognostic evaluation of these patients.