Persistent Atrial Tachyarrhythmias Research Articles

Cardiac Magnetic Resonance in Patients with Suspected Tachycardia-Induced Cardiomyopathy: The Impact of Late Gadolinium Enhancement and Epicardial Fat Tissue.

Tachycardia-induced cardiomyopathy (TIC) is a reversible subtype of dilated cardiomyopathy (DCM) resulting from sustained supraventricular or ventricular tachycardia and diagnosed by the normalization of left ventricular ejection fraction (LVEF) after stable sinus rhythm restoration. The aim of this study was to determine the contribution of cardiac magnetic resonance (CMR) to the differential diagnosis of TIC and DCM with persistent atrial arrythmias in patients hospitalized for the first time with heart failure (HF) with reduced LVEF of nonischemic origin. A total of 29 patients (age: 58.2 ± 16.9 years; males: 65.5%; average EF: 37.0 ± 9.5%) with persistent atrial tachyarrhythmia and first decompensation of HF without known coronary artery diseases were included in this study. The patients successfully underwent cardioversion and were observed for 30 days. The study population was divided into groups of responders (TIC patients; N = 16), which implies achieving FF > 50% or its increase > 10% in 30 days of TIC, and non-responders (N = 13). The increase in left ventricle (LV) volumes measured using CMR was significantly higher in the non-responder group when compared with the responders (114.8 mL ± 25.1 vs. 68.1 mL ± 10.5, respectively, p < 0.05). Non-responders also demonstrated decreased interventricular septum thickness (9.1 ± 0.8 vs.11.5 ± 1.3, respectively, p < 0.05). Late gadolinium enhancement (LGE) was observed in 12 patients (41.4%). The prevalence of LGE was increased in the non-responder group (25.0% vs. 65.1%, respectively, p = 0.046). Notably, a septal mid-wall LGE pattern was found exclusively in the non-responders. Epicardial adipose tissue thickness was decreased in the non-responder group versus the TIC patients. Conclusion: Patients with TIC were found to have smaller atrial and ventricular dimensions in comparison to patients with DCM. In addition, LGE was more common in DCM patients.

Atrial fibrillation progression after cryoablation vs. radiofrequency ablation: the CIRCA-DOSE trial.

Atrial fibrillation (AF) is a chronic progressive disorder. Persistent forms of AF are associated with increased rates of thromboembolism, heart failure, and death. Catheter ablation modifies the pathogenic mechanism of AF progression. No randomized studies have evaluated the impact of the ablation energy on progression to persistent atrial tachyarrhythmia. Three hundred forty-six patients with drug-refractory paroxysmal AF were enrolled and randomly assigned to contact-force-guided RF ablation (CF-RF ablation, 115), 4 min cryoballoon ablation (CRYO-4, 115), or 2 min cryoballoon ablation (CRYO-2, 116). Implantable cardiac monitors placed at study entry were used for follow-up. The main outcome was the first episode of persistent atrial tachyarrhythmia. Secondary outcomes included atrial tachyarrhythmia recurrence and arrhythmia burden on the implantable monitor. At a median of 944.0 (interquartile range [IQR], 612.5-1104) days, 0 of 115 patients (0.0%) randomly assigned to CF-RF, 8 of 115 patients (7.0%) assigned to CRYO-4, and 5 of 116 patients (4.3%) assigned to CRYO-2 experienced an episode of persistent atrial tachyarrhythmia (P = .03). A documented recurrence of any atrial tachyarrhythmia ≥30 s occurred in 56.5%, 53.9%, and 62.9% of those randomized to CF-RF, CRYO-4, and CRYO-2, respectively; P = .65. Compared with that of the pre-ablation monitoring period, AF burden was reduced by a median of 99.5% (IQR 94.0%, 100.0%) with CF-RF, 99.9% (IQR 93.3%-100.0%) with CRYO-4, and 99.1%% (IQR 87.0%-100.0%) with CRYO-2 (P = .38). Catheter ablation of paroxysmal AF using radiofrequency energy was associated with fewer patients developing persistent AF on follow-up.

Tahikardijom indukovana kardiomiopatija kao potencijalno reverzibilni uzrok srčane slabosti

Cardiac arrhythmias often coexist with heart failure and can be its cause or consequence. Tachycardia-induced cardiomyopathy most often occurs as a consequence of persistent atrial tachyarrhythmias, such as atrial fibrillation and atrial flutter. Accelerated heart rate leads to systolic and diastolic dysfunction of the left ventricle with its consequent dilation together with changes at the neurohumoral and cellular levels. Clinical presentation varies from asymptomatic tachycardia to end-stage heart failure. Tachycardia-induced cardiomyopathy is an often unrecognized and potentially reversible cause of heart failure. The exact prevalence of tachycardiomyopathy is difficult to determine since the diagnosis is made retrospectively, based on echocardiographically confirmed recovery of the left ventricular function after adequate treatment of the arrhythmia. The most effective treatment is catheter ablation of the arrhythmia. Other treatments include electrical cardioversion, pharmacological rhythm and/ or rate control, and pacemaker implantation with ablation of the atrioventricular node

Predictors of tachycardia-induced cardiomyopathy in patients with first-time decompensation of chro­nic heart failure with reduced left ventricular ejection fraction of nonischemic etiology and persistent atrial tachyarrhythmia

Aim To identify possible predictors of tachycardia-induced cardiomyopathy (TICMP) in patients with newly developed decompensated chronic heart failure (CHF) of nonischemic origin with reduced left ventricular ejection fraction (LV EF) and with persistent atrial tachyarrhythmias.Material and methods This study included 88 patients with newly developed decompensated CHF of nonischemic origin with reduced LV EF and persistent atrial tachyarrhythmias. Resting 12-lead electrocardiography (EGC) and transthoracic echocardiography (EchoCG) were performed upon admission and following the electrical impulse therapy for all patients. Also, 24-h ECG monitoring was performed to confirm sinus rhythm stability. After recovery of sinus rhythm, outpatient monitoring was performed for three months, including repeated EchoCG to evaluate the dynamics of heart chamber dimensions and LV EF.Results The patients were divided into two groups based on the increase in LV EF: 68 responders (TICMP patients with a LV EF increase by &gt;10%) and 20 non-responders (patients with an increase in LV EF by &lt;10% during 3 months following the sinus rhythm recovery). According to results of the baseline EchoCG, LV EF did not significantly differ in the two subgroups (TICMP, 40±8.3 %, 18-50 % and non-responders, 38.55±7.9 %, 24-50 %); moreover, the incidence of cases with LV EF &lt;30% did not differ either (9 patients TICMP and 2 non-responders, р=1.0). TICMP patients compared to non-responders, had significantly smaller left atrial dimensions (4.53±1.14 (2-7) cm and 5.68±1.41 (4-8) cm, р=0.034; 80.8±28.9 (27-215) ml and 117.8±41.3 (46-230) ml, р=0.03, respectively) and left ventricular end-systolic volume (ESV) (67.7±33.1 (29-140) ml and 104.5±44.7 (26-172) ml, р=0.02, respectively). The effect of major EchoCG parameters on the probability of TICMP development was assessed by one-factor and multifactor regression analyses with adjustments for age and sex. The probability of TICMP increased with the following baseline EchoCG parameters: end-diastolic volume (EDV) &lt;174 ml [odd ratio (OR), 0.115, 95 % confidence interval (CI): 0.035-0.371], ESV &lt;127 ml [OR, 0.034, 95 % CI: 0.007-0.181], left atrial volume &lt;96 ml [OR, 0.08 , 95 % CI: 0.023-0.274], right ventricular dimension &lt;4 cm [OR, 0.042 , 95 % CI: 0.005-0.389].Conclusion Among patients with newly developed decompensation of CHF with reduced LV EF of non-ischemic origin and persistent atrial arrhythmias, TICMP was detected in 72 % of patients. The probability of TICMP did not depend on baseline EF and duration of arrhythmias, but increased with the following baseline EchoCG parameters: EDV&lt; 174 ml, ESV&lt; 127 ml, left atrial volume &lt;96 ml, right ventricular dimension &lt;4 cm. The multifactorial analysis showed that a right atrial volume &lt;96 ml is an independent predictor for the development of TICMP.

Cryoballoon catheter ablation or drug therapy to delay progression of atrial fibrillation: A single-center randomized trial.

Delaying atrial fibrillation (AF) progression is a key goal in cardiovascular treatment. However, numbers of previously published studies on delayed AF progression are relatively limited. The purpose of this study was to determine whether a cryoballoon catheter ablation (CA) strategy could delay AF progression compared to anti-arrhythmic drug (AAD) treatment in patients with paroxysmal AF. A total of 204 subjects were enrolled in the trial, including 102 in the cryoballoon CA group and 102 in the AAD group. Participants were followed up with for 36 months. The primary study endpoint was the first occurrence of persistent atrial tachyarrhythmia, while secondary endpoints included the event rates of persistent atrial tachyarrhythmia at 1 and 2 years. The primary safety endpoint was serious adverse events. Overall, the 36-month follow-up was completed by 154 subjects (75.5%). At 3 years, documented progression from paroxysmal AF to persistent atrial tachyarrhythmia had occurred in 2 of the 102 patients assigned to undergo cryoballoon CA [2.203% (95% confidence interval (CI), 0.554-8.537)] and in 17 of the 102 patients assigned to receive AADs [20.223% (95% CI, 13.040-30.604)] [hazard ratio (HR), 0.107; 95% CI, 0.043-0.262; P < 0.001]. Lower rates of progression in the cryoballoon CA group compared to the AAD group were already obvious at 1 year [1.053% (95% CI, 0.149-7.238) vs. 5.284% (95% CI, 2.233-12.237)] [HR, 0.193; (95% CI, 0.039-0.956; P = 0.09)] and 2 years [2.203% (95% CI, 0.554-8.537) vs. 12.430% (95% CI, 7.066-21.371)] (HR, 0.169; 95% CI, 0.057-0.501, P < 0.001). Serious adverse events occurred in 7 of the 102 patients (6.9%) in the cryoballoon CA group and 9 of the 102 patients (8.8%) in the AAD group. Cryoballoon CA was superior to AAD therapy in preventing the occurrence of persistent atrial tachyarrhythmia in patients with paroxysmal AF who had not received prior rhythm control therapy. Serious adverse events were rare.

Linear lesions for treating the recurrence of persistent atrial tachyarrhythmia after cryoballoon ablation of atrial fibrillation

There is no consensus on the most effective radiofrequency ablation strategy for the initial or repeated treatment of persistent atrial tachyarrhythmia (ATa). To describe success and complication rates after the creation of left atrial (LA) linear lesions for recurrent persistent ATa following an index cryoballoon pulmonary vein isolation (PVI), and to identify predictors of ATa recurrence. During March 2013 to March 2020, we prospectively included all consecutive patients undergoing repeat procedures for the treatment of persistent ATa. Radiofrequency ablation consisting of the creation of linear lesions: a roofline, a mitral isthmus and/or septal line, and a cavotricuspid isthmus line. All patients were prospectively followed up for ATa recurrence. Overall, 133 patients underwent 170 procedures after initial cryoballoon PVI (n=715). At least one pulmonary vein reconnection was observed in 60 patients (45.1%), all of whom underwent successful re-disconnection. After all the procedures, >90% of patients had a lesion pattern consisting of a roofline, a mitral isthmus and/or septal line, and a cavotricuspid isthmus line. ATa was terminated in 41 patients (35%). There were three cases of tamponade (3/170 procedures, 1.8%). Ninety-two patients (69.2%) were in sinus rhythm after a median (interquartile range) of 36 (21-53) months since the index cryoballoon PVI. Diagnosis-to-ablation time and LA area were predictors of recurrence in multivariable analysis. The creation of linear lesions is a safe and effective treatment strategy for the recurrence of persistent ATa after cryoballoon PVI. Longer diagnosis-to-ablation time and larger LA area were predictive of ATa recurrence.

Prevalence of extra-appendage thrombosis in non-valvular atrial fibrillation and atrial flutter in patients undergoing cardioversion: a large transoesophageal echo study.

The aim of our study was to evaluate the prevalence of left atrial cavity and appendage thrombosis in patients undergoing cardioversion for non-valvular atrial tachyarrhythmias. In persistent atrial tachyarrhythmias, 90% of thromboses are reported to be located inside the left atrial appendage. This prevalence refers to old studies and meta-analysis in a mixed population of valvular and non-valvular atrial fibrillation. Left atrial cavity thrombosis in non-valvular atrial fibrillation has not been investigated recently in large-scale studies. A total of 1,420 consecutive adult patients with paroxysmal or persistent atrial tachyarrhythmias, candidates to cardioversion, who opted for a transoesophageal echocardiography-guided strategy, were enrolled in the study. Mitral stenosis, rheumatic valve disease and mechanical prostheses were excluded. In total there were 91 thrombi in 87 patients with a prevalence of 6.13% (87/1,420). Patients with left atrial thrombosis had predisposing clinical and echo characteristics (heart failure, lower ventricular function and higher atrial volume). Except for one case in which the thrombus was located in the left atrial cavity (0.07%), and three in the right appendage, all thromboses were detected in the left atrial appendage. Extra-appendage thrombosis is a very rare finding in non-valvular persistent and paroxysmal atrial tachyarrhythmias and, when present, a left appendage thrombus is usually concomitant.

96-15: Atrial tachyarrhythmias in patients after surgical CryoMaze ablation procedure

Purpose of the study: The CryoMaze ablation procedure was developed as a surgical alternative to incisional treatment for atrial fibrillation. Incomplete lines can decrease the efficacy of the ablation procedure and can be proarrhythmic. The aim of this study is to determine incidence and mechanisms of atrial tachyarrhythmias occurring after surgical CryoMaze. We also studied the efficacy of completing surgical lines by RF catheter ablation to maintain sinus rhythm. Methods: Fourty-eight consecutive patients who required surgical CryoMaze ablation for persistent atrial fibrillation as an adjunct to a cardiac surgery were enrolled in the study. All patients had a 7-day ECG Holter 3 months after the surgical CryoMaze. Patients with documented paroxysmal or persistent atrial arrhythmias on the ECG Holter underwent an electrophysiological study with the right and left atria electroanatomical mapping using a CARTO3 navigation system. According to the protocol, patients in sinus rhythm were tested with incremental atrial pacing to induce atrial tachyarrhythmias after all gaps in surgical lines had been re-ablated using RF catheter ablation. If persistent atrial tachycardia was recorded at the beginning of the study, the tachycardia was mapped and ablated as the first step, which was followed by finalization of the surgical lines. All patients were followed-up for 24 months with repeated 7-day ECG Holters Summary of results: Thirteen (27%) patients had persistent and 12 (25%) patients had paroxysmal atrial tachyarrhythmia on the 7-day ECG Holter. Persistent arrhythmias were later confirmed during the electrophysiological study as atrial fibrillation in 5 patients, typical isthmus-dependent atrial flutter in 4 patients, 2 peri-mitral flutters, 1 roof dependent flutter and 1 focal atrial tachycardia from the inter-atrial septum. In patients with sinus rhythm in the beginning of the study, surgical lines were re-ablated in all patients. In 3 cases, incremental atrial pacing induced different focal atrial tachycardias after all surgical ablation lines had been finalized. All spontaneous and inducible arrhythmias were successfully mapped and ablated. Twenty-three out of 25 patients who underwent catheter ablation after surgical CryoMaze remained in sinus rhythm without antiarrhythmic medication during the 24-month follow-up. Conclusion: One quarter of patients after surgical CryoMaze suffer from persistent atrial tachyarrhythmias and another quarter have paroxysmal atrial arrhythmias. Catheter ablation of these tachyarrhythmias and finalization of surgical lines is effective approach to treat patients with documented atrial arrhythmias after surgical CryoMaze.

Improvement of left ventricular function in patients with persistent atrial tachyarrhythmia induced cardiomyopathy undergoing radiofrequency ablation

Purpose: To investigate the alteration of left ventricular function in subjects with persistent atrial tachyarrhythmia induced cardiomyopathy (TIC) undergoing radiofrequency ablation, and to study the pathogenesis and effective treatment of TIC. Methods: A total of 25 cases with persistent atrial tachyarrhythmia and impaired left ventricular systolic function were studied (16 men and 9 women, aged 53.3 ± 15.2 years), and all subjects underwent electrophysiological study and radiofrequency ablation of atrial tachyarrhythmia under the guidance of CARTO system during 2006.9-2011.8. Indexes related to cardiac function, including left ventricular end diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF), New York Heart Association functional classification (NYHA class), 6 minutes walking test (6MWT), N-terminal pro-brain natriuretic peptide (BNP) and 24 hours average heart rate (AHR), were analyzed at the time point of 7 days, 3 and 6 months after the procedure as well as 1 day before ablation. Results: No refractory atrial arrhythmia recurred in all cases after ablation, compared with LVEDD (51.7 ± 4.5 mm), LVEF (39.0% ± 4.3%), number of patients with NYHA class IV and III (n = 17), 6MWT (212 ± 56 m), BNP (3622 ± 1860 ng/L) and AHR (112.5 ± 23.2 bpm) before ablation, the index of LVEDD (45.2 ± 3.3 mm; 41.7 ± 2.5 mm; 40.5 ± 3.1 m), BNP (2429 ± 1355 ng/L; 1530 ± 866 ng/L; 1300 ± 520 ng/L), total number of patients of NYHA class IV and III (n = 11; 3; 2) and AHR (73.3 ± 15.3 bpm; 68.7 ± 13.5 bpm; 66.3 ± 13.6 bpm) significantly decreased (P 47 m; 305 ± 37 m; 313 ± 41 m) greatly increased (P ）in 7 days, 3 and 6 months after ablation respectively. There was a statistical difference between 7 days and 3 or 6 months after ablation in above-mentioned indexes (P P > 0.05), no significant difference existed between 3 and 6 months in all indexes (P > 0.05). Conclusion: long-lasting atrial arrhythmia with rapid ventricular response could impair left ventricle function, which could be reversed within weeks after successful ablation and restoration of sinus rhythm.

Characteristics of Patients with Left Atrial Appendage Thrombus Detected by Transesophageal Echocardiography

Background: Transesophageal echocardiography (TEE) is often performed for prevention of strokes in patients with atrial tachyarrhythmia (atrial fibrillation; AF, atrial flutter; AFL) before cardioversion or catheter ablation. Some patients show left atrial appendage thrombus (LAAT) despite taking warfarin. We aimed to clarify the characteristics of patients with LAAT while taking warfarin. Methods: We studied 169 patients (124 males, mean age 65±11 yrs) who had TEE before cardioversion or catheter ablation for atrial tachyarrhythmia between 2008–2010 and retrospectively assessed the clinical, echocardiographic and electrocardiographic variables before TEE. All patients were taking warfarin. Results: Twelve patients (AF 139, AFL 30 and cardioversion 39, catheter ablation 130) had LAAT. Among these 12 patients, 62 had persistent atrial tachyarrhythmia and 48 patients had structural heart disease (25 prior ischemic cardiomyopathy, 4 hypertrophic cardiomyopathy and 6 non-ischemic cardiomyopathy). Left ventricular ejection fraction, persistent arrhythmia, prior heart failure and structural heart disease were revealed as significant variables. Conclusion: Patients with persistent arrhythmia, structural heart disease or prior heart failure might have high risk for LAAT before cardioversion or catheter ablation.

A clinical and health-economic evaluation of pulmonary vein encircling ablation compared with antiarrhythmic drug treatment in patients with persistent atrial fibrillation (Catheter Ablation for the Cure of Atrial Fibrillation-2 study)

Catheter Ablation for the Cure of Atrial Fibrillation 2 study is a prospective, randomized trial aimed to demonstrate the efficacy of catheter ablation with combined lesions in the right and left atria, in preventing atrial fibrillation (AF) recurrences among patients with recurrent persistent AF refractory to one antiarrhythmic drug, in comparison with the best pharmacological therapy. Enrolment is limited to patients aged between 18 and 70 years who have experienced at least one documented relapse of persistent AF during antiarrhythmic drug therapy. One hundred and twenty-six patients will be randomized to ablation or antiarrhythmic drug therapy in a 2 : 1 manner. In the ablation group, the patients will undergo right and left atrial linear ablation. Control group patients will be treated with the best antiarrhythmic drug. After an initial blanking period of 2 months patients will be followed for 24 months. Primary endpoint of the study is the absence of documented persistent atrial tachyarrhythmias relapse during the first 24 months after the blanking period. Enrolment is scheduled in 14 centres in Italy, UK, Austria, and Finland. Seventy-two patients have currently been enrolled. This study will provide important data about the efficacy of catheter ablation in comparison with antiarrhythmic drugs for the treatment of persistent AF.

Intra- and interatrial conduction delay: implications for cardiac pacing.

Atrial conduction disorders are frequent in elderly subjects and/or those with structural heart diseases, mainly mitral valve disease, hyperthrophic cardiomyopathies, and hypertension. The resultant electrophysiological and electromechanical abnormalities are associated with a higher risk of paroxysmal or persistent atrial tachyarrhythmias, either atrial fibrillation, typical or atypical flutter or other forms of atrial tachycardias. Such an association is not fortuitous because intra- and interatrial conduction abnormalities delays disrupt (spatial and temporal dispersion) electrical activation, thus promoting the initiation and perpetuation of reentrant circuits. Preventive therapeutic interventions induce variable, sometimes paradoxical effects as with the proarrhythmic effect of class I antiarrhythmic drugs. Similarly, atrial pacing may promote proarrhythmias or an antiarrhythmic effect according to the pacing site(s) and mode. Multisite atrial pacing was conceived to correct, as much as possible, abnormal activation induced by spontaneous intra- or interatrial conduction disorders or by single site atrial pacing, which are situations responsible for commonly refractory arrhythmias. Atrial electrical resynchronization can also be used to correct mechanical abnormalities like left heart AV dyssynchrony resulting from intraatrial conduction delays.

Effectiveness of rapid atrial pacing for termination of drug refractory atrial fibrillation: results of a dual chamber implantable cardioverter defibrillator trial.

There is increasing interest in the use of an implantable cardioverter defibrillator (ICD) to manage atrial tachyarrhythmias. Although device-based shock therapy is highly effective in terminating persistent atrial tachyarrhythmias, atrial overdrive pacing may also be useful, particularly when this therapy is applied early after the onset of an arrhythmia. A dual-chamber ICD (Medtronic 7250 Jewel AF(R)) has been studied in 267 patients with drug-refractory symptomatic AF. The patients were enrolled as part of multicenter clinical trial to evaluate the safety and efficacy of the device to manage atrial tachyarrhythmias in the absence of a standard ventricular ICD indication. The device discriminates atrial tachycardia (AT) from atrial fibrillation (AF) based on cycle length and regularity, and employs multiple methods of atrial overdrive pacing as well as shocks to terminate tachyarrhythmia episodes. Patients were followed for an average of 15.8 +/- 9.3 months. A majority (63%) of patients presented with a history of persistent AF and 34% presented with a history of paroxysmal AF. The pacing therapies terminated 54% of AT episodes and 27% of AF episodes. In patients with persistent AF, 75% of the AT/AF episodes that were successfully terminated by pacing lasted <or=9 minutes. When the pacing therapies failed, episodes lasted for several hours and 50% of the episodes received at least one shock. The results of this trial suggest that pace-termination plays an important role in device-based management of atrial tachyarrhythmias. It is estimated that early pace-termination of AT/AF episodes may reduce the need for device-based shocks among patients with persistent AF by about half.

Cause of atrioventricular block in patients after heart transplantation.

The precise incidence and cause of atrioventricular block (AVB) after heart transplantation remain uncertain. After surgery, immediate and follow-up electrocardiograms from 1047 consecutive patients who underwent heart transplantation were reviewed for AVB and correlated with clinical symptoms, laboratory data, rejection grade, and echocardiogram and coronary angiography findings. A total of 113 patients demonstrated various kinds of AVB; the incidence was 10.8%. First-degree AVB occurred in 87 patients, 37 of whom also demonstrated persistent atrial tachyarrhythmias (ATAs). In 30 patients, first-degree AVB occurred 7 days to 120 months after heart transplantation. Among those, 88% demonstrated cellular rejection, and 20% developed transplant coronary artery disease (TCAD). Fifty patients demonstrated first-degree AVB without ATA, 32 of whom developed AVB from operative day 7 to 156 months. The incidence of cellular rejection was significantly lower (36%, P<0.01), and the rejection was less severe. In 18 patients, AVB occurred early postoperatively (0-7 days), and most were secondary to surgical injury. Second-degree AVB Mobitz I occurred in six patients (four patients with TCAD and two patients undergoing percutaneous transluminal coronary angioplasty). One patient developed Mobitz II during coronary artery stenting. Complete AVB (CAVB) occurred in 19 patients. Nine episodes of CAVB occurred during endomyocardial biopsy or coronary angiography, and four occurred immediately after heart transplantation as the result of surgical insult. These results indicate that first-degree AVB is causatively related to cellular rejection and TCAD-induced atrial conduction disturbance. Second-degree AVB and CAVB were mainly the consequences of surgical and catheter intervention injury.

Congenital intrapericardial aneurysms of the left atrium.

A patient with congenital intrapericardial aneurysm/diverticulum of the left atrium diagnosed preoperatively is described. A review of the 16 previously reported cases revealed that the majority of the patients present with palpitation and are found to have an abnormal cardiac shadow on chest radiography, as did this patient. The aneurysm appears to cause systemic emboli and paroxysmal or persistent atrial tachyarrhythmias which are often resistant to medical therapy. The presence of the aneurysm is suggested by an abnormal contour of the left cardiac border in the postero-anterior chest radiograph and this can be confirmed by angiocardiography. Surgical excision of the aneurysm is indicated in all patients to prevent the occurrence or recurrence of systemic emboli and atrial arrhythmias. Our patient has remained free of symptoms since her operation 14 months ago.