BACKGROUND: Maze operation is aimed for the restoration of sinus rhythm. But restoration of atrial mechanical function has not been demonstrated in all patients converted to sinus rhythm. METHOD: From Apr. 1994 to Feb. 1996, maze operations were performed in 32 pts (M:F=13:19, mean age 47.1+/-9.0 years) combined with valvular surgery(n=26), CABG(n=3), and others(n=3). Presence of atrial mechanical function was serially examined before discharge, in 3mo, 6mo and 1 yr using Doppler echocardiography. RESULTS: In 22 patients(pts), sinus rhythm was maintained without antiarrhythmic agents. In 4 patients antiarrhythmic agent was required to maintain sinus rhythm while in another 4 patients showed paroxysmal Af despite of the treatment with antiarrhythmic agents. In 30 pts with sinus rhythm or paroxysmal Af, right atrial function was restored in all pts while left atrial function was restored in only 19/30(63%). Peak A velocity and A/E ratio were 0.38+/-0.12m/s, 0.74, respectively on tricuspid inflow(TI), and 0.46+/-0.14m/s, 0.40, respectively on mitral inflow(MI ). MI peak A velocity and A/E ratio were significantly lower than the 16 control postoperative pts (0.75<0.29, 0.80 : p+/-0.01). In pts with atrial mechanical function, the duration of Af was significantly shorter than patients without atrial function (1.9+/-2.9 yr vs 7.1+/-3.0 yr : p<0.01), but no significant differences in the LA size and volume. CONCLUSION: Maze operation is effective in restoring sinus rhythm. But restoration of sinus rhythm was not always associated with restoration of atrial mechanical function, and the restored atrial function was incomplete. The duration of Af could be a markker for predicting the restoration of atrial function.
Atrial Fibrillation ; Atrial Function ; Atrial Function, Left ; Atrial Function, Right ; Echocardiography, Doppler ; Humans

BACKGROUND: Maze operation is aimed for the restoration of sinus rhythm. But restoration of atrial mechanical function has not been demonstrated in all patients converted to sinus rhythm. METHOD: From Apr. 1994 to Feb. 1996, maze operations were performed in 32 pts (M:F=13:19, mean age 47.1+/-9.0 years) combined with valvular surgery(n=26), CABG(n=3), and others(n=3). Presence of atrial mechanical function was serially examined before discharge, in 3mo, 6mo and 1 yr using Doppler echocardiography. RESULTS: In 22 patients(pts), sinus rhythm was maintained without antiarrhythmic agents. In 4 patients antiarrhythmic agent was required to maintain sinus rhythm while in another 4 patients showed paroxysmal Af despite of the treatment with antiarrhythmic agents. In 30 pts with sinus rhythm or paroxysmal Af, right atrial function was restored in all pts while left atrial function was restored in only 19/30(63%). Peak A velocity and A/E ratio were 0.38+/-0.12m/s, 0.74, respectively on tricuspid inflow(TI), and 0.46+/-0.14m/s, 0.40, respectively on mitral inflow(MI ). MI peak A velocity and A/E ratio were significantly lower than the 16 control postoperative pts (0.75<0.29, 0.80 : p+/-0.01). In pts with atrial mechanical function, the duration of Af was significantly shorter than patients without atrial function (1.9+/-2.9 yr vs 7.1+/-3.0 yr : p<0.01), but no significant differences in the LA size and volume. CONCLUSION: Maze operation is effective in restoring sinus rhythm. But restoration of sinus rhythm was not always associated with restoration of atrial mechanical function, and the restored atrial function was incomplete. The duration of Af could be a markker for predicting the restoration of atrial function.
Atrial Fibrillation ; Atrial Function ; Atrial Function, Left ; Atrial Function, Right ; Echocardiography, Doppler ; Humans

OBJECTIVEElectrical restitution was believed to be a determinant responsible for the stability of heart rhythm. Although numerous studies focused on the role of action potential duration restitution (APDR) in the initiation and maintenance of ventricular fibrillation (VF), the relationship between atrial APDR and atrial fibrillation (AF) has not been fully understood. This study aims to investigate the characteristics of APDR of left atrium (LA) and right atrium (Rs) in canines and the relevance to induction of AF.

METHODSMonophasic action potential (MAP) was recorded from LA and RA in 14 canines using the MAP recording-pacing combination catheter. APDR, plotted as action potential duration (APD) on the preceding diastolic interval (DI), was assessed by use of programmed stimulation with a single extrastimulus (S1S2) at LA and RA. Episodes of AF were recorded and analyzed.

RESULTSAPD90 was significantly shorter in the LA than that in the RA [(157.4 +/- 43.5) ms vs. (170.9 +/- 37.9) ms, P < 0.05]. The mean slope of the APDR curve by S1S2 in the LA was significantly greater than that in the RA (1.3 +/- 0.4 vs. 0.9 +/- 0.3, P < 0.05). The incidence of induced AF was significantly higher in the LA than in the RA (11/18 vs. 7/18, P < 0.05).

CONCLUSIONSThe APDR and MAP characteristics are not uniform between atrium, which may be one of the important mechanisms responsible for the initiation of AF. Heterogeneity of APDR between LA and RA might create critical gradients or a dispersion of repolarization and substrate for re-entrant arrhythmias and vulnerability to AF.

Action Potentials ; Animals ; Atrial Fibrillation ; etiology ; physiopathology ; Atrial Function, Left ; physiology ; Atrial Function, Right ; physiology ; Cardiac Pacing, Artificial ; Dogs ; Electric Countershock

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a kind of inherited cardio-myopathy, which is characterized by fibro-fatty replacement of right ventricular myocardium, leading to ventricular arrhythmia. However, rapid atrial arrhythmias are also common, including atrial fibrillation, atrial flutter and atrial tachycardia. Long term rapid atrial arrhythmia can lead to further deterioration of cardiac function. This case is a 51-year-old male. He was admitted to Department of Cardiology, Peking University Third Hospital with palpitation and fatigue after exercise. Electrocardiogram showed incessant atrial tachycardia. Echocardiography revealed dilation of all his four chambers, especially the right ventricle, with the left ventricular ejection fraction of 40% and the right ventricular hypokinesis. Cardiac magnetic resonance imaging found that the right ventricle was significantly enlarged, and the right ventricular aneurysm had formed; the right ventricular ejection fraction was as low as 8%, and the left ventricular ejection fraction was 35%. The patients met the diagnostic criteria of ARVC, and both left and right ventricles were involved. His physical activities were restricted, and metoprolol, digoxin, spironolactone and ramipril were given. Rivaroxaban was also given because atrial tachycardia could cause left atrial thrombosis and embolism. His atrial tachycardia converted spontaneously to normal sinus rhythm after these treatments. Since the patient had severe right ventricular dysfunction, frequent premature ventricular beats and non-sustained ventricular tachycardia on Holter monitoring, indicating a high risk of sudden death, implantable cardioverter defibrillator (ICD) was implanted. After discharge from hospital, physical activity restriction and the above medicines were continued. As rapid atrial arrhythmia could lead to inappropriate ICD shocks, amiodarone was added to prevent the recurrence of atrial tachycardia, and also control ventricular arrhythmia. After 6 months, echocardiography was repeated and showed that the left ventricle diameter was reduced significantly, and the left ventricular ejection fraction increased to 60%, while the size of right ventricle and right atrium decreased slightly. According to the clinical manifestations and outcomes, he was diagnosed with ARVC associated with arrhythmia induced cardiomyopathy. According to the results of his cardiac magnetic resonance imaging, the patient had left ventricular involvement caused by ARVC, and the persistent atrial tachycardia led to left ventricular systolic dysfunction.
Arrhythmogenic Right Ventricular Dysplasia/complications* ; Atrial Fibrillation ; Humans ; Male ; Middle Aged ; Stroke Volume ; Ventricular Function, Left ; Ventricular Function, Right

No abstract available.
Atrial Function, Left ; Sprains and Strains

BACKGROUND: The aim of study is to identify the dependence of right ventricular (RV) free wall longitudinal deformation on ventricular loading through segmental approach in relatively large number of patients with atrial septal defect (ASD). METHODS: Patients with ASD (n = 114) and age matched healthy children (n = 60) were echocardiographically examined the day before percutaneous device closure and within 24 hours afterwards. RV free wall deformation parameters, strain (small je, Ukrainian) and strain rate (SR), were analyzed in the apical (small je, Ukrainian(A), SR(A)) and basal (small je, Ukrainian(B), SR(B)) segments. Measured deformation parameters were adjusted for RV size (small je, Ukrainian(AL), SR(AL), small je, Ukrainian(BL), SR(BL)) by multiplying by body surface area indexed RV longitudinal dimension. Regression analyses determined the relationships of these deformation parameters with RV loading parameters that were measured by catheterization. RESULTS: small je, Ukrainian(BL) and SR(BL) were not different between pre-closure patients and controls (p = 0.245, p = 0.866), and were decreased post-closure (p = 0.001, p = 0.018). Post-closure small je, Ukrainian(BL) was lower than in controls (p = 0.001). Pre-closure small je, Ukrainian(AL) and SR(AL) were higher than in controls (p = 0.001, p < 0.001), but decreased after closure (all p < 0.001). The pulmonary to systemic flow ratio was related to procedural differences of small je, Ukrainian(BL) (p = 0.017) and of SR(BL) (p = 0.019). RV end diastolic pressure was negatively related to post-closure small je, Ukrainian(BL) (p = 0.020) and post-closure SR(BL) (p = 0.012), and the procedural SR(BL) difference (p = 0.027). CONCLUSION: The longitudinal deformation of the RV basal segment is dependent and its remodeling is also dependent on volume loading in children with ASD.
Blood Pressure ; Body Surface Area ; Catheterization ; Catheters ; Child* ; Heart Septal Defects, Atrial* ; Humans ; Ventricular Function, Right

BACKGROUND: The left atrium functions as a reservoir for blood stored during ventricular systole, a conduit for pulmonary venous flow during ventricular diastole, and as a pump augmenting left ventricular filling during atrial systole. Cardiac angiography and Doppler echocardiography have been used in the assessment of atrial function. These measurements are, however, quite sensitive to ventricular and atrial loading conditions. Instantaneous pressure-volume relations of the left atrium have been described by a time-varying elastance model in the isolated left atrium and intact circulation in animal models. The mitral stenosis can be characterized hemodynamically as increased afterload of the left atrium. Percutaneous mitral balloon valvuloplasty, which results in a dramatic increase in the mitral orifice area in patients with mitral stenosis, is a well-suited clinical model for physiological assessment of the left atrial function in response to acute change of the left atrial afterload. The purpose of this study was 1) to evaluate the feasibility of the left atrial pressure-volume loop using automatic boundary detection method, 2) to obtain the left atrial pressure-volume loop in patients with mitral stenosis and to compare with that of normal controls, and 3) to assess the changes of the left atrial wall tesion and stroke work after percutaneous mitral balloon valvuloplasty in patients with mitral stenosis using the left atrial pressure-volume relations. METHODS: Twelve patients had simultaneous measurements of left atrial pressure and left atrial volume using trasseptal catheterization and two-dimensional echocardiography with automatic boundary detection technology. The left atrial pressure-volume was constructed by a computer workstation interfaced with an ultrasound system. Left atrial volumetric parameters, areas of A and V loops, and peak wall tension were measured and compared before and after percutaneous mitral balloon valvuloplasty. RESULTS: 1) The left atrial pressure-volume loop could be obtained without complications in the control group as well as in patients with mitral stenosis. 2) The left atrial peak wall tension and A and V loop areas were significantly increased in mitral stenosis compared to the control group. 3) Left atrial maximal volume, minimal volume and volume before active atrial contraction were significantly increased in mitral stenosis compared to control group. 4) Left atrial ejection fraction and left atrial active emptying fraction were significantly reduced in mitral stenosis. Left atrial passive emptying fraction was slightly reduced in mitral stenosis compared to control group without statistical significance. 5) Left atrial peak wall tension and A loop area were significantly reduced after percutaneous mitral balloon valvuloplasty. 6) There were no significant changes in left atrial maximal volume, minimal volume, volume before active atrial contraction, total volume change, passive emptying volume, active emptying volume, passive emptying fraction, active emptying fraction, V loop area and left atrial ejection fraction after percutaneous mitral balloon valvuloplasty. CONCLUSION: The left atrial stroke work and peak wall tension can be assessed quantitatively using left atrial pressure-volume relations in patients with mitral stenosis and those are significantly reduced after percutaneous mitral balloon valvuloplasty. The analysis of left atrial pressure-volume loop is a potentially useful means in the assessment of left atrial function.
Angiography ; Atrial Function ; Atrial Function, Left* ; Atrial Pressure ; Balloon Valvuloplasty* ; Catheterization ; Catheters ; Diastole ; Echocardiography ; Echocardiography, Doppler ; Heart Atria ; Humans ; Mitral Valve Stenosis* ; Models, Animal ; Stroke ; Systole ; Ultrasonography

BACKGROUND AND OBJECTIVES: Heart failure rarely occurs in patients with thyrotoxicosis (6%), with half of the cases having left ventricular dysfunction (LVD). Although a few studies reported isolated right heart failure in thyrotoxicosis, there has been no evaluation of relationship between LVD and right ventricular dysfunction (RVD). SUBJECTS AND METHODS: We enrolled 12 patients (mean age: 51+/-11 years, 9 females) diagnosed as having thyrotoxicosis with heart failure and LVD {left ventricular ejection fraction (LVEF) <40%}, and divided them into two groups {Group I with RVD defined as tricuspid annular plane excursion (TAPSE) less than 15 mm and Group II without RVD}. Clinical features, laboratory variables, and echocardiographic parameters were compared between two groups. RESULTS: RVD was found in 6 (50%) patients. On admission, there were no significant differences between the two groups in clinical features, laboratory variables, or echocardiographic parameters including atrial fibrillation {6 vs. 5, not significant (NS)}, heart rate (149+/-38 vs. 148+/-32/min, NS), LVEF (36.7+/-9.5 vs. 35.1+/-6.3%, NS), or the tricuspid regurgitation peak pressure gradient (TRPPG, 30.9+/-2.0 vs. 36.3+/-9.3 mmHg, NS). After antithyroid treatment, all achieved an euthyroid state and both ventricular functions were recovered. All data, including the recovery time of LVEF and the change of heart rate between two groups, displayed no significant differences. CONCLUSION: In half of patients, RVD was combined with thyrotoxicosis-associated LVD. There were no differences in clinical factors or hemodynamic parameters between patients with and without RVD. This suggests that RVD is not secondary to thyrotoxicosis-associated LVD.
Atrial Fibrillation ; Heart Failure ; Heart Rate ; Hemodynamics ; Humans ; Stroke Volume ; Thyrotoxicosis ; Tricuspid Valve Insufficiency ; Ventricular Dysfunction, Left ; Ventricular Dysfunction, Right ; Ventricular Function

Background: Atrial Septal Defect (ASD) is one of the most common congenital cardiac defects. Both surgical and catheter occlusion of the defect has been found effective and safe in eliminating interatrial shunting. However, knowledge of the response of the left side of the heart to ASD closure is incomplete. Objective: This study assessed the left side of the heart\u2019s response to ASD closure over a 6-month follow-up period. Subjects and method: 148 patients of ASD ostium secundum with an average age of 26.13 +/- 14.24 years (2-62 years) and the mean ASD size of 24.92 +/- 7.97 mm has been studied by echocardiography before and after atrial septal defect closure. Results: The right ventricular diameter and hemodynamics were improved after ASD closure (p<0.0001). The left ventricular end-diastolic diameter and volume increased significantly after ASD closure (p<0.0001). Conclusions: The left ventricular systolic function was unaffected by ASD closure. The right side of the heart\u2019s response to ASD closure over 6-month follow-up period decreased significantly (p<0.0001).
Atrial septal defect ; ASD ; left ventricular function

BACKGROUND: Non-dippers were reported as showing different left atrial function, compared to dippers, but no study to date investigated the changes in the left atrial function according to the diurnal blood pressure pattern, using tissue Doppler and strain imaging. METHODS: Forty never treated hypertensive patients between 30 and 80 years of age were enrolled in this study. Patients were classified as non-dippers when, during night time, they had a blood pressure decrease of less than 10%. Strain of the left atrium was measured during late systole, and peak strain rates of the left atrium were measured during systole, early and late diastolic periods. RESULTS: The left atrial expansion index, left atrial active emptying volume and left atrial active emptying fraction were all significantly increased in non-dippers. They also had increased values of mean peak left atrial strain (dippers = 21.26 +/- 4.23% vs. non-dippers = 24.91 +/- 5.20%, p = 0.02), strain rate during reservoir (dippers = 1.29 +/- 0.23 s-1 vs. non-dippers =1.52 +/- 0.27 s-1, p = 0.01) and contractile period (dippers = -1.38 +/- 0.24 s-1 vs. non-dippers = -1.68 +/- 0.32 s-1, p < 0.01). CONCLUSION: Strain and strain rate acquired from color Doppler tissue imaging demonstrate exaggerated reservoir and booster pump function in never-treated, non-dipper hypertensive patients. These methods are simple and sensitive for the early detection of subtle changes in the left atrial function.
Atrial Function, Left ; Blood Pressure ; Circadian Rhythm ; Echocardiography ; Heart Atria ; Humans ; Hypertension ; Sprains and Strains ; Systole