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Supernormal left ventricular diastolic function in triathletes.

We studied the structural and functional heart adaptations of 52 male triathletes compared with those of 22 active, nonathletic men, by 2-dimensional Doppler echocardiography. Left ventricular diastolic function was evaluated by recording transmitral flow velocities. To exclude the influences of preload, left atrial pressure, and aortic pressure, left ventricular diastolic function was also evaluated by pulsed Doppler tissue imaging. Significant differences in cardiac structure and function were observed between the 2 groups. In the triathletes, the left ventricular diastolic function was completely normal, despite signs of mixed eccentric and concentric left ventricular hypertrophy, and this function was better than that in the control group. We measured 2 aspects of the late passive diastolic filling period in the triathletes: ASEAC value (the amplitude of excursion of the interventricular septal endocardium at the end of left ventricular diastole just after atrial contraction); and the time between onset of the P wave on the electrocardiographic tracing and onset of systolic septal movement on M-mode echocardiography. Pulsed Doppler tissue imaging confirmed these results. The E/A ratios (peak early left ventricular diastolic motion velocity divided by the peak atrial systolic motion velocity), measured by pulsed Doppler tissue imaging, yielded even more evidence for supernormal left ventricular diastolic function in the triathletes. Left ventricular relaxation and filling properties were measured along the longitudinal and transverse axes by pulsed Doppler tissue imaging, which was useful for evaluating left ventricular diastolic function. We determined that triathletes may develop supernormal left ventricular diastolic function with increased diastolic reserves.

Adult↗

Acute and long-term results of radiofrequency ablation of common atrial flutter and the influence of the right atrial isthmus ablation on the occurrence of atrial fibrillation.

AIMS: The purpose of this study was to evaluate the acute success rate and long-term efficacy of radiofrequency ablation of common type atrial flutter (AFL) by using a standardised anatomical approach in a large series of patients and to assess the influence of right atrial isthmus ablation on the occurrence of atrial fibrillation. There are no large scale prospective or retrospective multicentre studies for radiofrequency ablation of AFL. METHODS AND RESULTS: The study population consisted of 363 consecutive patients with AFL (mean age 58+/-16 years, 265 men) who underwent radiofrequency ablation at the inferior vena cava-tricuspid annulus (IVC-TA) isthmus using a standardised anatomic approach. Bidirectional isthmus block at the IVC-TA was achieved in 328 patients (90%). Following radiofrequency ablation, 343 patients (95%) were followed for a mean of 496+/-335 days. During the follow-up period, 310 patients (90%) remained free of AFL recurrences. Multivariate analysis identified five independent predictors of AFL recurrence: fluoroscopy time (p<0.001), atrial fibrillation after AFL ablation (p=0.01), lack of bidirectional block (p=0.02), reduced left ventricular function (p=0.035) and right atrial dimensions (p=0.046). Atrial fibrillation occurrence was significantly reduced after AFL ablation (112 in 343 patients, 33%) as compared to occurrence of atrial fibrillation before radiofrequency ablation (198 in 363 patients, 55%, p<0.001). CONCLUSIONS: The current anatomical ablation approach for AFL and criteria for evaluation of the IVC-TA isthmus block is associated with an acute success rate of 90% and a long-term recurrence rate of 10%. Radiofrequency ablation of common AFL results in a significant reduction in the occurrence of atrial fibrillation.

Acute Disease↗

Cerebral embolism and hyperthyroidism.

Three different cases of cerebral embolism occurring in combination with hyperthyroidism are reported. Case 1; a healthy 37-year-old woman presented with sudden onset of left hemiparesis and left sided hypoesthesia of all modalities. Embolism in area of the right middle cerebral artery was confirmed by angiography and CT scan. Laboratory examination revealed hyperthyroidism and anemia. Antithyroid treatment brought about euthyroid function while slight hemiparesis remained present. Case 2; a 79-year-old woman who suffered from hypertension for one year had sudden onset of disorientation and left hemiparesis. Electrocardiogram showed atrial fibrillation. The CT scan indicated infarction in the right anterior and middle cerebral artery. The patient was diagnosed as having masked hyperthyroidism. Although antithyroid medication reduced it to euthyroid condition, the patient is now bedridden with hemiparesis. Case 3; a 45-year-old man who had partial thyroidectomy for Basedow's disease and had been treated with antithyroid and antiarrhythmic therapy for 10 years. Suddenly, he was in coma with dilated right pupil and left hemiplegia. Atrial fibrillation and hypothyroid function were observed. CT scan indicated hemorrhagic infarction in the territory of the middle cerebral artery with transtentorial herniation. He died on the 59th day of hospitalization following an episode of bronchopneumonia. On the basis of the cases presented here as well as on the basis of those described in the literature it appears that thyrotoxic patients with atrial fibrillation exhibit high incidence of cerebral embolism, and prophylactic anticoagulant therapy may be recommended.

Adult↗

Analysis of azide-insensitive Ca2+-dependent ATPase activity in atrial specimens from patients with coronary or valvular heart disease.

The activity of the azide-insensitive Ca2+-dependent ATPase (highly enriched in myofibrillar ATPase activity) was studied in specimens of both right and left atria which were taken from patients with ischemic and/or valvular heart disease during coronary by pass and/or valvular substitution. A significantly lower enzymatic activity was found in atrial specimens from patients with left ventricular heart failure in comparison to the atrial fragments obtained from the patients with normal heart function. Such an inhibition reflected a significant increase in the Km of the enzyme for ATP and was associated with a concomitant reduction in Vmax, both more evident in the left atrial fragments. Moreover, tissue homogenates of atrial specimens from failing hearts exhibited a lower protein SH group content when compared to the atrial homogenates from the heart with normal left ventricular heart function.

Azides↗

Regulation of plasma ANF after increases in afterload in conscious dogs.

Although atrial stretch is the primary stimulus for atrial natriuretic factor (ANF) secretion, hormones may directly affect ANF secretion or may indirectly influence ANF by changing left ventricular afterload, thereby altering atrial stretch. To determine whether direct effects are important for the release of ANF in vivo, we measured changes in plasma ANF and in atrial wall function in the conscious dog after the administration of vasopressin, angiotensin II, and phenylephrine and by mechanically increasing left ventricular afterload by partial aortic occlusion. Injections of phenylephrine, angiotensin II, and arginine vasopressin (AVP) that were chosen to cause similar changes in systemic arterial pressure resulted in similar changes in atrial pressure and diameter. Maximum V wave atrial wall stress increased to 283 +/- 12, 311 +/- 41, 327 +/- 24, and 277 +/- 22 g/cm2 for AVP, angiotensin, phenylephrine, and occlusion, respectively, and plasma ANF increased to 242 +/- 81, 248 +/- 62, 299 +/- 95, and 190 +/- 53 pg/ml. There were significant linear correlations between left ventricular afterload and left atrial pressure, and each method for increasing left ventricular afterload shifted the position to the left on an atrial pressure-diameter, compliance curve, by a similar degree. Thus changes in left ventricular afterload result in changes in atrial wall function and similar changes in plasma ANF. No hormonal-specific increase in plasma ANF was found in conscious dogs after increases in afterload.

Angiotensin II↗

Isolation of the pulmonary veins in patients with permanent atrial fibrillation secondary to mitral valve disease.

OBJECTIVE: To assess the efficacy of surgical isolation of the pulmonary veins for re-establishing sinus rhythm in patients with atrial fibrillation secondary to mitral valve disease. METHODS: Thirty-three (67% were women) patients with permanent atrial fibrillation and indication for surgical correction of the mitral valve underwent surgical isolation of the pulmonary veins. Their mean age was 56.3+/-10 years, preoperative NYHA functional class was 3.2+/-0.6, left atrial size was 5.5+/-0.9 cm, and ejection fraction was 61.3+/-13%. The surgical technique consisted of a circumferential incision surrounding the 4 pulmonary veins, excision of the left atrial appendage, and a perpendicular incision originating in the inferior margin of the circumferential incision isolating the pulmonary veins down to the mitral valve. Early arrhythmias were aggressively treated with cardioversion. RESULTS: The mean follow-up was 23.9+/-17 months, and 3 patients died in the postoperative period. Ten patients required electrical cardioversion in the postoperative period; 87% had sinus rhythm in the last medical visit, and 33% were using amiodarone. CONCLUSION: Isolation of the pulmonary veins associated with mitral valve surgery is an effective and safe technique for maintaining sinus rhythm in patients with permanent atrial fibrillation.

Adult↗

[Spontaneous echo contrast in atrium with rheumatic heart disease by transesophageal echocardiography and its potential relation to thrombus].

The prevalence of atrial spontaneous echo contrast (SEC) and mural thrombus were evaluated in 154 consecutive patients undergoing transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE). By TEE, SEC was observed in 106 patients (68.8%). Of them, 103 were seen in left atrium and only 3 were seen in right atrium. No SEC and mural thrombus were seen by TTE. Patients with mitral stenosis were in 82 of 154 patients, SEC was seen in 74 of those 82 patients (90%). Mechanical stenosis in mitral orifice is a predominant factor. Our analysis showed significant relation between the presence of SEC and atrial fibrillation (P < 0.005); left atrial enlargement (P < 0.001) and cardiac days function (P < 0.005). Of the 106 patients with SEC, 41 (38.7%) were in sinus rhythm and only 8 with the left atrial diameter > 60 mm. Left atrial mural thrombus was noted in 52/154 (33.6%), 42 of those 52 were patients with SEC (80%), which also suggest a significant relation between the presence of SEC and mural thrombus (P < 0.025). Thus SEC is a common phenomenon in patients with rheumatic heart disease. Its relation to thrombus formation and prognostic significance requires further evaluation.

Adolescent↗

Effect of mitral valve repair/replacement surgery on atrial arrhythmia behavior.

BACKGROUND AND AIMS OF THE STUDY: Few data have been published on the effects of mitral valve surgery on atrial rhythm. The study aims were to determine the effects of surgery on: (i) persistence of atrial fibrillation (AF); (ii) measures of left atrial and ventricular dimensions; and (iii) ECG P-wave duration. METHODS: A retrospective case-note review of 92 patients with chronic mitral regurgitation was undertaken. Variables determined included prevalence and duration of AF; incidence of new-onset or persistence of AF after surgery; rhythm changes in relation to age, gender, left atrial and ventricular dimensions and function, anti-arrhythmic drug usage and ECG P-wave duration in sinus rhythm prior to surgery. RESULTS: Only 4/47 (8.5%) patients with any history of AF before surgery were in sinus rhythm at six months after surgery. All 28 patients with persistent AF for >12 months and 41/45 (91%) in sinus rhythm before surgery retained these rhythms after surgery. The left atrial dimension was decreased after surgery, in the whole group (51.3 +/- 9.0 versus 48.4 +/- 9.5 mm; p = 0.011) and in the subgroup in sinus rhythm, but not in the subgroup in AF. The left ventricular end-diastolic dimension decreased in the group as a whole (60.6 +/- 6.2 versus 53.0 +/- 8.7 mm; p = 0.0001) and in both subgroups after surgery. In 24 patients with 12- lead ECGs in sinus rhythm before and three months after surgery, P-wave duration remained unchanged. However, this measure decreased in the 18 patients in sinus rhythm consistently, but increased in the six patients continuing to have paroxysmal AF after surgery. CONCLUSION: Mitral valve surgery alone restored sinus rhythm in only 8.5% of patients with any previous history of AF. Concomitant anti-arrhythmic procedures should be considered for all patients with AF who undergo mitral valve surgery.

Aged↗

[Percutaneous mitral commissurotomy and Lutembacher syndrome].

INTRODUCTION: Lutembacher syndrome refers to the rare combination of congenital atrial septal defect and acquired mitral stenosis. This condition is usually treated surgically by mitral valve operation with concomitant closure of the atrial septal defect. MATERIALS AND METHODS: Between 1993 and 2003, 4 patients with congenital Lutembacher syndrome had percutaneous mitral commissurotomy without closure of the atrial septal defect at our institution. The 4 patients were very symptomatic with right-sided heart failure signs and NYHA functional class III-IV. RESULTS: The procedure was carried out successfully for the four patients. Mitral valve area increased from 0.87 to 1.97 cm2 at mean; left atrial pressure decreased from 28.2 to 12.7 mmHg and the mean valve mitral gradient was reduced from 15.5 to 3.9 mmHg. Functional and clinical improvement was observed in all the cases. During a mean follow up of 55 +/- 29 months, our 4 patients remain pauci symptomatic under medical treatment. CONCLUSION: The percutaneous treatment of the Lutembacher syndrome is currently a possible alternative to the surgery among patients having an anatomy favourable to the procedure.

Adult↗

Focal ablation of chaotic atrial rhythm in an infant with cardiomyopathy.

Chaotic atrial rhythm in infants has been defined similar to multifocal atrial tachycardia in adults, implying a multifocal etiology. However, its ECG appearance resembles atrial fibrillation, which sometimes has a unifocal ectopic mechanism amenable to catheter ablation. Curative focal radiofrequency ablation was performed in a 4-month-old infant with chaotic atrial rhythm and dilated cardiomyopathy. Left ventricular function subsequently returned to normal. Reversibility of associated cardiomyopathy supports aggressive rhythm management of chaotic atrial rhythm. In this patient, the unifocal origin allows insight into the pathophysiology of the rhythm and demonstrates the potential utility of catheter ablation for refractory cases.

Atrial Fibrillation↗

Functional capacity after traditional Chinese medicine (qi gong) training in patients with chronic atrial fibrillation: a randomized controlled trial.

Evidence indicates that low energy expenditure protocols derived from traditional Chinese medicine may benefit patients with cardiac impairment; therefore, the authors carried out a randomized controlled trial to test a 16-week medically assisted qi gong training program for the physical rehabilitation of patients with stable chronic atrial fibrillation and preserved left ventricular function. Functional capacity variation was evaluated using the 6-minute walk test, which was performed at baseline, at the end of the intervention, and after 16 weeks. Thirty men and 13 women (mean age, 68+/-8 years) were randomized to the intervention protocol or to a wait-list control group. Qi gong training was well tolerated and, compared with baseline, trained patients walked an average 114 meters more (27%) at the end of treatment (P<.001) and 57 meters more (13.7%) 16 weeks later (P=.008). Control subjects showed no variation in functional capacity. These results seem promising and deserve confirmation with further research.

Aged↗

Functionally atrialized parchment-like right ventricle with extensive myocardial fibrosis of left ventricle.

A 18-year-old female with unusual type of parchment-like right ventricle died of intractable congestive heart failure was reported. A catheter study revealed the absence of systolic contraction of the right ventricle. The pressure tracing curve in the right ventricle was virtually the same as in the right atrium. At autopsy, there was an extensive myocardial fibrosis of the left ventricle in addition to the almost total absence of the myocardium of the right ventricle. The case was considered to be a unique type of idiopathic cardiomyopathy.

Adolescent↗

[Left ventricular function in coronary disease. Gamma cineangiocardiography at equilibrium with right atrial pacing and nitroglycerine].

25 patients (2 normal and 23 coronary artery disease) were studied by 99m Tc gated blood pool scans at rest, with right atrial pacing, right atrial pacing and nitroglycerine, and finally nitroglycerine alone. Total and regional ejection fractions were measured and the induced and reversible asynergy with right atrial pacing and nitroglycerine was also assessed.

Cardiac Pacing, Artificial↗

Left ventricular filling dynamics: influence of left ventricular relaxation and left atrial pressure.

Peak rapid filling rate (PRFR) is often used clinically as an index of left ventricular relaxation, i.e., of early diastolic function. This study tests the hypothesis that early filling rate is a function of the atrioventricular pressure difference and hence is influenced by the left atrial pressure as well as by the rate of left ventricular relaxation. As indexes, we chose the left atrial pressure at the atrioventricular pressure crossover (PCO), and the time constant (T) of an assumed exponential decline in left ventricular pressure. We accurately determined the magnitude and timing of filling parameters in conscious dogs by direct measurement of phasic mitral flow (electromagnetically) and high-fidelity chamber pressures. To obtain a diverse hemodynamic data base, loading conditions were changed by infusions of volume and angiotensin II. The latter was administered to produce a change in left ventricular pressure of less than 35% (A-1) or a change in peak left ventricular pressure of greater than 35% (A-2). PRFR increased with volume loading, was unchanged with A-1, and was decreased with A-2; T and PCO increased in all three groups (p less than .005 for all changes). PRFR correlated strongly with the diastolic atrioventricular pressure difference at the time of PRFR (r = .899, p less than .001) and weakly with both T (r = .369, p less than .01) and PCO (r = .601, p less than .001). The correlation improved significantly when T and PCO were both included in the multivariate regression (r = .797, p less than .0001). PRFR is thus determined by both the left atrial pressure and the left ventricular relaxation rate and should be used with caution as an index of left ventricular diastolic function.

Angiotensin II↗

Left ventricular morphology and function in mild to moderate essential hypertension.

150 males with mild to moderate essential hypertension [EH] were examined echocardiographically and the findings in the left ventricle [LV] were compared with those in 20 normotensive men. Increased LV wall thickness and LV mass was found in 81% and 67% of hypertensives respectively in contrast with a complete absence of LV hypertrophy in normotensives. The former showed also a tendency to the concentric type hypertrophy, which can be considered a characteristic feature of the 2nd stage [WHO] EH. There was an almost uniform incidence of asymmetric septal hypertrophy in the two groups [12 vs. 10%]. Decreased LV end-systolic wall stress in EH was a sign of compensatory myocardial hypertrophy without LV dilatation. The hypertensives exhibited a normal or slightly elevated systolic LV function. On the other hand, some indirect indices of LV properties [peak rate of LV relaxation and left atrial dimension] were indicative of diastolic function impairment. A slight but significant correlation between the degree of LV hypertrophy and systemic blood pressure at rest was found in a part of hypertensive patients. The study indicates that mild to moderate EH leads to some changes in LV morphology and function, which can be easily recognized by echocardiography.

Adult↗

Efficacy of a simple left atrial procedure for chronic atrial fibrillation in mitral valve operations.

BACKGROUND: We have devised a simple surgical procedure to be performed on the posterior wall of the left atrium for the treatment of chronic atrial fibrillation (AF) associated with mitral valve disease. The effectiveness of this procedure for serial mitral valve operations was then evaluated. We postulated that chronic AF associated with mitral valve disease could be attributable to a distended left atrium. The refractory period of the distended left atrium was significantly shorter in the left posterior atrial wall, especially at the base of the left atrial appendage and at the orifice of the left posterior pulmonary vein. We hypothesized that the left posterior atrial wall with its shorter fibrillatory cycle length would act as a driver for maintaining the AF, and therefore, surgical ablation of this critical area in the left atrium could terminate the chronic AF. METHODS: The surgical patients were divided into two groups. In group 1 (control group), 15 patients with chronic AF were operated on by the mitral valve procedure only. In group 2, 36 patients underwent this procedure in combination with a concomitant mitral valve operation. The disappearance rate of the AF was estimated by electrocardiography, and atrial function was estimated by transthoracic and transesophageal echocardiography. RESULTS: The chronic AF had been reduced significantly or eliminated at discharge in 4 of 15 patients (26.7%) in the group 1, versus 31 of 36 patients (86%) in group 2 (p < 0.05). In group 2, 29 of the 31 patients (94%) whose AF had disappeared recovered the atrial kick of their right atrium, and 21 patients (22/31; 71%) recovered the atrial kick of their left atrium. CONCLUSIONS: Surgical ablation of the posterior wall of the left atrium was effective in the treatment of chronic AF associated with mitral valve disease. This simple procedure could restore a sinus rhythm and also recovered atrial systolic function. We conclude that the left atrium may act as a driver for sustaining AF in mitral valve disease.

Aged↗