Comparison of long term outcome in patients with or without aortic ring abscess treated surgically for aortic valve infective endocarditis

OBJECTIVE

To assess the long term prognostic significance of aortic valve ring abscess in patients with aortic endocarditis.

PATIENTS

A consecutive series of 75 patients who had surgery for aortic infective endocarditis between 1981 and 1989; 35 had aortic ring abscesses (group 1) and 40 did not (group 2). Mean age did not differ between the two groups. Prosthetic valve endocarditis was present in 17% of group 1 and 5% of group 2. Pneumococcal or beta haemolytic streptococcal endocarditis was more common in patients with native valve endocarditis who had aortic ring abscesses (20% v 5%).

DESIGN

Cohort analysis.

RESULTS

In-hospital mortality (11.4% v 7.5%) and 10 year survival (56% v 66%) were not significantly different between groups 1 and 2. In patients with native valve endocarditis, 10 year survival was 62% and 66%, respectively for patients with or without ring abscess, and 10 year reintervention-free survival was 38% v 58% (p = 0.11). In these patients, the presence of an intercurrent illness, severe congestive heart failure before surgery, and use of valved conduits for surgical treatment were predictors of poorer long term survival. At follow up residual aortic regurgitation was documented in 72% of patients in group 1 and 26% in group 2 (p < 0.01).

CONCLUSIONS

Aortic valve ring abscess is not an independent marker of poor long term outcome in patients with infective endocarditis. However, as residual aortic regurgitation appears frequent at follow up, specific surgical techniques should be considered in patients with paravalvar abscesses.

[Influence of anti-arrhythmia agents on heart rate variability]

Since analysis of heart rate variability (HRV) is able to identify subjects at risk of sudden death and as antiarrhythmics can interfere with this prognosis, the objective of this study was to determine whether antiarrhythmics (AA) modified the HRV measured on a 24-hour Holter recording and after rapid ventricular stimulation and whether the initial HRV and its possible modification during treatment with AA were correlated with the results of AA treatment in patients with ventricular tachycardia (sustained VT). The HRV was studied in 50 patients with heart disease and spontaneous sustained VT, reproduced by programmed ventricular stimulation. This analysis was performed at baseline with antiarrhythmic treatment consisting of low-dose beta-blocker and quinidines in 26 patients (group I) or amiodarone in 24 patients (group II). Treatment was effective (i.e. prevented induction of VT) in 9 patients in group I (group la) and 5 patients in group II (group IIa). Treatment was ineffective in the other 17 patients of group I (group Ib) and 19 patients of group II (group IIb). The initial HRV was similar in the patients of groups Ia and Ib or groups IIa and IIb. Temporal analysis did not reveal any significant variation of HRV during AA treatment. In contrast, spectral analysis of HRV and the HRV observed during ventricular stimulation demonstrated a significant reduction of this parameter (p < 0.05 for groups I and II combined).

IN CONCLUSION

the initial HRV is not predictive of the results of treatment. Quinidines and amiodarone tend to decrease HRV regardless of the effect of the AA on the prevention of VT.

[Effects of age on the response to Tilt test in patients with malaise or syncopes]

The diagnosis of vasovagal malaise or syncope, suspected from the clinical history, may be confirmed by the tilt test. The aim of this study was to assess the effects of age on the results of this test in 346 patients who had unexplained malaise or syncope. Thirty-one patients were 7 to 19 years of age (group I), 59 were 20 to 40 (group II), 72 were 41 to 60 (group III) and 184 were 61 to 85 years old (group IV). The patients were maintained in the dorsal decubitus position for 20 minutes and then raised to 70 degrees until a malaise was observed or for a maximum of 40 minutes. The malaise or syncope was reproduced by the tilt test in 135 cases (39%). The number of positive responses was comparable in group I, II, III and IV (45, 42, 32 and 40%, respectively). The time before the malaise occurred was also similar in the four groups (17, 19, 15 and 20 minutes, respectively). Two responses to the tilt test characterised the different age groups: the greater number of malaises occurring independently of a drop in blood pressure or change in heart rate ("psychiatric" syncope) in group II compared with groups I, III and IV (40% versus 7, 9 and 9.5%); the higher frequency of pure vasodepressive forms in group IV compared with groups I, II and III (66% versus 28.5, 32 and 39%). In conclusion, the probability of a positive tilt test does not change with age. The mechanisms of the symptoms produced is the only difference observed with age.

[Heart rate response to ventricular stimulation]

Analysis of heart rate variability (HRV) by Holter monitoring is the method of choice for assessing the cardiac autonomic regulation. Rapid ventricular stimulation also provokes changes in the autonomic nervous system tone. The aim of this study was to compare time and frequency domain analysis of HRV (Elatec version 3.02) with variations of HR observed after incremental ventricular stimulation to 200/min in 130 patients. In 80 patients, ventricular stimulation provoked an initial acceleration in HR followed by a slowing with a variation of over 10%. In the other 50 patients, these variations were not observed. Holter analysis of HRV showed concordance between the two methods. In time domain analysis, the standard deviation of normal R-R intervals, the coefficient of variability [(CV = SD/mean RR) and percentage of adjacent RR intervals with a difference of more than 50 msec (pNN 50) were significantly reduced in the abnormal group, the respective values in the normal and abnormal groups being: SD 122 vs 72 msec; CV 15 versus 9% and pNN50 9 versus 5%)]. In frequency domain analysis, there was a reduction of low and high frequency spectra and of the ratio of low/high frequencies in abnormal subjects. The authors conclude that the disappearance of HR changes after ventricular stimulation is correlated to the absence of HRV on Holter recording. This simple test may be performed systematically during electrophysiological investigations. The measurements are reproductible and the results are not affected by arrhythmias or technical problems of quality recording by the Holter method which may affect analysis of HRV.