Study of atrial function using echocardiographic automatic boundary detection following external or internal cardioversion for idiopathic atrial fibrillation.

INTRODUCTION: The aim of this study was to evaluate the validity of an echocardiographic method of automatic boundary detection (ABD) in the assessment of the degree of atrial dysfunction in patients who had undergone external or internal cardioversion for idiopathic atrial fibrillation. METHODS: The study population included 31 patients (mean age 48 +/- 6.5 years) with idiopathic atrial fibrillation. The patients were randomised into two groups: Group 1 (14 patients, 8 +/- 3.13 joules), where internal cardioversion was applied, and Group 2 (17 patients, 200-360 joules), where external cardioversion was used for restoration of sinus rhythm. During the following 24 hours the ABD method was used in both groups to assess the following functional indices for both the left and the right atrium: a) total fractional change of atrial area (delta1), b) passive change of atrial area (delta2), c) change of atrial area due to atrial contraction (delta3) and d) index of % atrial expansion (delta4). RESULTS: All patients in both groups were successfully cardioverted (100%, p: NS). Post-cardioversion indices delta1-delta4 for both left and right atria did not differ between the 2 groups (p:NS). A negative correlation was found between left atrial function as assessed by ABD and the mean energy in joules delivered through the catheter in each patient for successful cardioversion (r = -0.55 to r = -0.67 and p = 0.04 to p = 0.01). However, no relevant correlations were found for the right atrium (p:NS). CONCLUSIONS: 1) The atrial dysfunction which follows the cardioversion of idiopathic atrial fibrillation (atrial stunning) is not related to the type of cardioversion (internal or external). 2) The higher the amount of energy delivered during internal cardioversion, the greater the degree of left atrial dysfunction observed.

Impaired systolic dysfunction of left ventricular longitudinal fibers: a sign of early hypertensive cardiomyopathy.

BACKGROUND: Atrioventricular plane displacement (AVPD) study by M-mode echocardiography can supply useful clinical information about left ventricular (LV) long-axis function. HYPOTHESIS: We assessed the hypothesis that AVPD estimation could be used to detect early hypertensive cardiomyopathy. METHODS: The study population included 81 hypertensive patients with normal LV ejection fraction and fractional shortening, and 50 age- and gender-matched healthy controls. By utilizing M-mode and apical views, the following parameters were estimated: early mitral flow peak velocity (E) and deceleration time (DT), peak velocity of late mitral flow (A), A/E ratio, isovolumic relaxation time (IVRT), total AVPD, AVPD motion during atrial systole (At), systolic AVPD (total AVPD-At), and At/total AVPD ratio. RESULTS: Of 81 hypertensive patients, 16 (19.7%) had a normal (Group 1) and 65 (80.3%) an impaired LV relaxation filling pattern (Group 2). Mean total AVPD-At was significantly lower in Group 2 than in Group 1 (7.1 +/- 2 vs. 10.3 +/- 3 mm, p<0.001) and in Group 1 compared with healthy subjects (10.3 +/- 3 vs. 13.1 +/- 1 mm, p<0.001). Mean At and At/total AVPD were significantly higher in Group 2 than in Group 1 (46.9 +/- 8.6 vs. 37.7 +/- 8.7%, p<0.001), but not in Group 1 compared with healthy subjects (37.7 +/- 8.7 vs. 36 +/- 6%, p>0.05). CONCLUSIONS: Hypertensive patients without overt systolic dysfunction demonstrate LV long-axis systolic dysfunction, while long-axis diastolic dysfunction always coexists with abnormal diastolic filling patterns. This suggests that long-axis systolic dysfunction precedes diastolic dysfunction at the same axis in hypertensive patients.

Right ventricle bipolar pacing may prevent appropriate biventricular pacing from two pacemakers. Case report.

This article reports on practical problems and possible solutions that may occur in case of upgrading a dual-chamber pacemaker by implanting a second left ventricular ventricular pacing, ventricular sensing, ventricular triggering (VVT) pacemaker. This therapeutic strategy was considered appropriate in the case of a 73-year-old patient with severe heart failure, who was scheduled to undergo coronary artery bypass surgery. A right-sided, dual-chamber pacemaker had been already implanted to the patient. The duration of the paced QRS complex was 220 ms and inter- and intraventricular dyssynchrony was documented in the echocardiographic study. We describe the methodological problems and possible solutions related to biventricular pacing following the abovementioned strategy.

The Contribution of the Left Atrioventricular Plane Displacement During Low Dose Dobutamine Stress Echocardiography in Predicting Recovery of Left Ventricular Dyssynergies.

The aim of this study was to assess the significance of the left systolic atrioventricular (AV) plane displacement during low dose dobutamine stress echocardiography (DSE), in predicting the recovery of left ventricular dyssynergies after revascularization. In 30 infarctiers with left ventricular dysfunction scheduled for RE (14 percutaneous transluminal coronary angioplasty and 16 coronary artery bypass graft) and in 25 age- and sex-matched healthy subjects, a DSE, using a 16 ventricular segment model and a four-grade scoring system for the assessment of regional wall motion of the left ventricle was performed. Prior and during DSE, the left systolic AV plane displacement was recorded from the apical four- and two-chamber views, by M-mode echo, at four left ventricular sites, corresponding to the septal, lateral, anterior, and inferior walls, both in patients and controls. The study was repeated in all patients 101 +/- 14 days after successful revascularization. Healthy subjects showed a significant increase of left systolic AV plane displacement at all left ventricular sites during dobutamine infusion (DI) (P < 0.001). Patients also exhibited a significant maximum increase of left systolic AV plane displacement during DSE only in the dyssynergic sites with functional improvement in the postrevascularization echocardiogram (P < 0.001). In the remaining dyssynergic sites, without functional improvement after revascularization, the left systolic AV plane displacement did not change (P > 0.05). Selecting a maximum LAVPD increase of >2 mm at any site of the left ventricule to predict recovery of the regional ventricular dyssynergies, results in a sensitivity of 91%, specificity of 83%, positive predictive value of 88%, and negative predictive value of 87%. When two-dimensional DSE was used for the detection of reversible dysfunction, sensitivity and specificity were found to be 81.5% and 87.5%, respectively, while the positive and negative predictive values were 90% and 78%, respectively. When the two methods were in agreement the sensitivity was 90%, the specificity 100%, and the positive and negative predictive values were 100% and 84.2%, respectively. The assessment of left systolic AV plane displacement during DI constitutes a new, simple, and accurate method in the prediction of left ventricular dyssynergy recovery after revascularization. The combination of this method and two-dimensional DSE are basic predictor markers of viability of dysfunctional myocardium. (ECHOCARDIOGRAPHY, Volume 13, November 1996)