An increase in plasma atrial natriuretic peptide concentration during exercise predicts a successful cardioversion and maintenance of sinus rhythm in patients with chronic atrial fibrillation

Baseline NT-ProBNP level predicts success of cardioversion of atrial fibrillation with flecainide

BACKGROUND

Patients with acute-onset symptomatic atrial fibrillation (AF) can be treated with flecainide. However, flecainide may induce arrhythmias and/or exaggerate heart failure. Therefore, validated markers to predict the efficacy of flecainide and prevent adverse effects are required. We hypothesised that lower NT-proBNP plasma levels correlate with higher success rates of cardioversion with flecainide in patients with AF.

METHODS

In this prospective single-centre study, we included 112 subsequent patients with acute-onset (< 24 h) symptomatic AF. Patients with symptoms of heart failure and ECG signs of ischaemia were excluded. Baseline laboratory measurements, including NT-proBNP, were done. Echocardiograms were performed ~ 2 weeks after restoration of SR.

RESULTS

Cardioversion with flecainide was successful in 91 patients (87 %). NT-proBNP was lower in patients with successful cardioversion (P < 0.001). Logistic regression indicated NT-proBNP as an independent predictor of successful cardioversion. A cut-off NT-proBNP value of 1550 pg/ml provided optimal test accuracy to predict successful cardioversion.

CONCLUSION

In patients with < 24 h of symptomatic AF, NT-proBNP levels up to 1550 pg/ml correlate with high success rates (94 %) of cardioversion with flecainide. Conversely, NT-proBNP higher than 1550 pg/ml correlates with poor success rates (36 %). Further research is needed to validate the predictive value of NT-proBNP for successful cardioversion with flecainide.

The influence of left ventricle diastolic function on natriuretic peptides levels in patients with atrial fibrillation

BACKGROUND

The diagnosis of the impaired left ventricle (LV) diastolic function during atrial fibrillation (AF) using traditional methods is very difficult. Natriuretic peptides seem to be useful for assessment of diastolic function in patients with AF.

AIM

To evaluate the influence of LV diastolic dysfunction on natriuretic peptides concentrations and to assess the diagnostic value of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) in patients with AF and impaired LV diastolic function.

METHODS

The study included 42 patients (23 males, 19 females), aged 58.6 +/- 8.2 years with nonvalvular persistent AF with preserved LV systolic function who were converted into sinus rhythm by DC cardioversion (CV) and maintained sinus rhythm for at least 30 days. Echocardiography (ECG), ANP, and BNP level measurements were taken at baseline 24 hours before CV and 24 hours and 30 days after CV. On the 30th day following CV in patients with sinus rhythm, Doppler ECG was performed to assess LV diastolic function.

RESULTS

Thirty days after CV, normal LV diastolic function in 15 patients and impaired diastolic function in 27 patients was diagnosed: 20 with impaired LV relaxation and seven with impaired LV compliance. During AF and 24 hours, and 30 days after sinus rhythm restoration, significantly higher ANP and BNP levels were observed in patients with LV diastolic dysfunction as compared to the subgroup with normal LV diastolic function. The average values of ANP during AF in patients with normal and impaired diastolic function were 167.3 +/- 70.1 pg/mL and 298.7 +/- 83.6 pg/mL, respectively (P < 0.001), and the average values of BNP in the above mentioned subgroups were 49.5 +/- 14.7 pg/mL and 145.6 +/- 49.6 pg/mL respectively (P < 0.001). While comparing the diagnostic value of both natriuretic peptides it was noted that BNP was a more specific and sensitive marker of impaired LV diastolic function. ANP value >220.7 pg/mL measured during AF identified patients with impaired LV diastolic function with 85% sensitivity and 90% specificity. BNP value >74.7 pg/mL proved 95% sensitive and 100% specific in the diagnosing of such a group.

CONCLUSIONS

The increase of ANP/BNP concentration in patients with AF results not only from the presence of AF, but also reflects the impaired LV diastolic function. Natriuretic peptides, especially BNP, may be useful in diagnosing LV diastolic dysfunction in patients with AF.

Use of bepridil in combination with Ic antiarrhythmic agent in converting persistent atrial fibrillation to sinus rhythm

BACKGROUND

It has been reported that bepridil is as good as amiodarone in converting persistent atrial fibrillation (AF) to sinus rhythm (SR). The conversion effect of bepridil alone is not always satisfactory, however. The efficacy of pharmacological cardioversion by the combination of bepridil and a class Ic antiarrhythmic drug for persistent AF is studied.

METHODS AND RESULTS

The participants comprised 37 consecutive patients in whom pharmacological cardioversion was conducted to treat persistent AF (duration 22.5+/-29.6 months). Each patient first received a class Ia or Ic antiarrhythmic drug, then bepridil alone, then a combined therapy of bepridil at 200 mg/day with a class Ic antiarrhythmic drug at a routine dose. Unaccompanied use of any of the antiarrhythmic drugs achieved pharmacological cardioversion in 14 (38%) of the 37 patients (single therapy group), whereas SR was restored by combination of bepridil and a class Ic antiarrhythmic drug in 22 (combined therapy group) of the remaining 23 patients. The duration of AF was significantly longer in the combined therapy group than in the single therapy group (28.3+/-31.0 vs 7.3+/-4.1 months).

CONCLUSION

Combined therapy of bepridil and a class Ic antiarrhythmic drug is efficient for pharmacological cardioversion of refractory long-lasting persistent AF.

Natriuretic peptide response to dynamic exercise in patients with atrial fibrillation

BACKGROUND

In patients with atrial fibrillation (AF) information regarding exercise release of atrial natriuretic peptide (ANP) is sparse and data on plasma brain natriuretic peptide (BNP) response to exercise is lacking. The aim of this study was to investigate plasma ANP and BNP response to exercise in patients with permanent AF and to assess if the response was different from the response in healthy age- and sex-matched control subjects.

METHODS

Plasma venous concentrations of ANP and BNP were determined at rest, at peak exercise and 30 min from the end of exercise in 38 patients with permanent AF and in 43 age- and sex-matched healthy control subjects.

RESULTS

Plasma concentrations of ANP and BNP were significantly higher in AF patients compared with the healthy control group at rest, peak exercise and after 30 min of recovery (p<0.0001). ANP and BNP increased significantly during exercise in both patients with AF and in the healthy control subjects (p<0.05). The increase in plasma concentration of ANP and BNP during exercise was significantly higher in AF patients compared with healthy controls (p=0.0002 for ANP; p<0.0001 for BNP). In the recovery period plasma BNP decreased significantly (p<0.0001) where as the decrease in plasma ANP was insignificant (p=0.4).

CONCLUSIONS

Patients with permanent AF have elevated levels of ANP and BNP at rest and exhibit much higher exercise release compared to healthy control subjects. This enhanced secretion of potent vasodilating and natriuretic agents may represent an important compensatory mechanism to improve exercise capacity in patients with AF.

The dubious value of echocardiographic and plasma ANP measurements in predicting outcome of cardioversion in patients with persistent atrial fibrillation

Atrial fibrillation (AF) is a common arrhythmia with important therapeutic and prognostic implications. An attempt to restore sinus rhythm is considered in most patients with AF. The aim of this study was to assess the value of echocardiographic examination and plasma atrial natriuretic peptide (ANP) evaluation in predicting the outcome of cardioversion and maintenance of sinus rhythm in patients with persistent AF.

METHODS

Eighty-one consecutive patients, aged 62+/-9 years, with AF of duration 4.7 months were subjected to an echocardiography examination and ANP assessment before cardioversion. The patients were predominantly hypertensive men with moderately enlarged left atrium and ejection fraction of left ventricle of about 50%. All patients were in controlled AF and had normalized blood pressure. In order to predict the outcome of cardioversion, and maintenance of sinus rhythm over a 1 month period, a multivariate logistic regression method was performed using the following variables: left atrial and left ventricular dimensions, left ventricular ejection fraction and plasma ANP levels.

RESULTS

Sixty-nine out of the 81 patients were successfully converted to sinus rhythm. At 1 month 57 patients remained in sinus rhythm. There were no statistical differences between sinus rhythm and AF group in baseline ANP levels (59.4 vs 64.2 pg/ml, consecutively), clinical and echocardiographic characteristics. In logistic regression analysis neither baseline echocardiographic variable nor ANP level, predicts successful cardioversion over a 1-month period of observation.

CONCLUSION

Echocardiographic data and ANP level should not be included as an important variable when considering patients for cardioversion.

Effects of Systolic Atrial Function on Plasma Renin Activity and Natriuretic Peptide Secretion after High Rate Atrial and Ventricular Pacing in Dogs

Rapid atrial rates cause electrical, structural remodeling, and neuro-humoral changes. This study compares the effects of mechanical remodeling on plasma renin activity (PRA) and atrial natriuretic peptide (ANP) secretion. Eight beagles were subjected to rapid atrial pacing (AP) at 400 beats/min for 16 days. After complete recovery of left ventricular function, they underwent rapid ventricular pacing (VP) at 240 beats/min of equal duration. Left atrial systolic maximal dimension (LAmax) and left atrial appendage (LAA) peak late emptying velocity (LAA-E) were assessed by echocardiography. Blood samples were taken from the right atrium and from the peripheral vein. LAmax after AP and VP enlarged significantly (2.16 +/- 0.21 cm vs 2.41 +/- 0.23 cm, P = 0.002). Compared with baseline, LAA-E velocities were significantly reduced (0.65 +/- 0.12 m/s vs 0.26 +/- 0.16 m/s, P = 0.001) after AP only. AP caused a significant elevation of PRA in right atrial (9.28 +/- 4.23 nmol/L per hour) and peripheral samples compared with baseline values (4.82 +/- 2.53 nmol/L per hour, P = 0.04). ANP levels increased after AP (1117.12 +/- 252.21 fmol/L) with respect to baseline values (824.37 +/- 159.08 fmol/L, P = 0.001). There was no difference in PRA and ANP levels between atrial and peripheral samples. Atrial size and impaired systolic appendage function play an important role in secretion of PRA and ANP. Both neuro-humoral pathways may be therapeutic targets in the treatment of patients with AF.

Concomitant recovery of atrial mechanical and endocrine function after cardioversion in patients with persistent atrial fibrillation

OBJECTIVES

The purpose of this study was to evaluate left atrial mechanical function recovery and plasma atrial natriuretic peptide (ANP) release following successful cardioversion of persistent atrial fibrillation (AF).

BACKGROUND

Atrial fibrillation is characterized by functional deterioration, loss of atrial contraction, and elevation of plasma ANP levels. The response of ANP release toward atrial mechanical function after cardioversion of AF has not been fully examined.

METHODS

We examined 29 patients with successfully cardioverted persistent AF in whom sinus rhythm was maintained for at least 30 days after cardioversion. We assessed mechanical function of the left atrium at 24 h and 7 and 30 days after cardioversion and evaluated plasma ANP level at the same time. Atrial mechanical function was assessed during echocardiographic examination by means of the peak velocity of the transmitral A-wave, early transmitral to atrial flow velocity ratio, and atrial filling fraction (AFF). The plasma ANP level was determined by the radioimmunoassay method.

RESULTS

Plasma ANP levels were significantly reduced from 59.4 +/- 16.6 pg/ml to 31.1 +/- 9.2 pg/ml at 24 h after successful cardioversion. Within 30 days, we noted progressive improvement of atrial systolic function (increase in AFF from 21% to 31%, p < 0.05). At the same time, plasma ANP levels gradually increased from 31.1 +/- 9.2 pg/ml at 24 h to 36.9 +/- 12.8 pg/ml on day 30 following cardioversion (p < 0.05).

CONCLUSIONS

Plasma ANP levels significantly decreased in patients with persistent AF after successful cardioversion. In the 30 days after cardioversion, gradual elevation of plasma ANP concentration was observed concomitantly with an increase of AFF. Plasma ANP release after successful cardioversion of persistent AF might be due to recovery of atrial mechanical function.

Atrial natriuretic peptide level after cardioversion of chronic atrial fibrillation

Heart endocrine studies concerning patients with chronic atrial fibrillation (AF) have become increasingly important. Atrial natriuretic peptide (ANP) is released from atrial myocytes. The increased level of ANP in patients with AF is probably caused by the hemodynamic effect of the arrhythmia. The aim of this study was to explore plasma ANP levels in patients with chronic AF and to describe plasma ANP concentration changes following sinus rhythm (SR) restoration. The study group was comprised of 42 patients, aged between 43 and 76 years with chronic AF (more than 1 month) and a relatively controlled ventricular response (85.8+/-11.3 beats/min). Plasma ANP levels were measured before and 24 h after AF cardioversion. The control group comprised of 11 subjects. All had normal SR without history of AF and were compatible in age, sex and concomitant diseases with the examined group. ANP level values were expressed as mean+/-standard deviation. The mean plasma ANP level in the AF group was significantly higher than in the control group (59.5+/-15.6 vs. 34.3+/-10.2 pg/ml, P<0,001). Electrical or pharmacological cardioversion was performed in 42 patients. SR was successfully restored in 35 patients. Plasma ANP concentrations decreased significantly from baseline values (from 59.4+/-16.6 to 31.4+/-15.0 pg/ml, P<0.001) 24 h after cardioversion in the successful group, while they remained unchanged (60.2+/-10.7 to 59.4+/-10.4 pg/ml, NS) in patients with an unsuccessful cardioversion.

CONCLUSION

The mean concentration of ANP in patients with chronic AF was nearly two-times higher than in the control group with sinus rhythm. Conversion to SR was associated with a significant decrease and normalization in plasma ANP concentrations.