End Of Atrial Fibrillation Research Articles

Right bundle branch block with changing axis at the end of atrial fibrillation

Changing axis has been reported [1–8] also during atrial fibrillation [9–11] or atrial flutter [12,13]. Changing axis has been also reported during acute myocardial infarction [14–25] associated with atrial fibrillation too [26,27] or at the end of atrial fibrillation [28,29], also during acute myocardial infarction [30,31]. Dissimilar electrocardiographic patterns associated with right bundle branch block have been described [32]. Changing bundle branch block [14,33], new right bundle branchblock [34], rightbundle branchconductiondisturbances [35] and intermittent right bundle branch block [18] have also been reported in literature. We present a case of a right bundle branch block with changing axis at the end of atrial fibrillation in a 57-year-old Italian woman. A 57-year-old Italian woman was admitted to the Emergency Department with an atrial fibrillation. She reported the onset of palpitations approximately 2 h before. The ECG was performed and it showed a right bundle branch block with an atrial fibrillation (Fig. 1). The patientwas admitted to the Cardiology Unit. No pericardial effusion was observed at echocardiographic evaluation. After restoration of sinusal rhythm, the ECG showed right bundle branch block with changing axis and it was confirmed on ECG's surface performed on the following day (Fig. 2). Also this case focuses attention on changing axis.

Left bundle branch block and changing axis deviation during acute myocardial infarction

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a left bundle branch block with changing QRS morphology and changing axis deviation. We present a case of a left bundle branch block with changing axis deviation in an 86-year-old Italian man admitted to the Cardiology Unit with an acute myocardial infarction. Also this case focuses attention on left bundle branch block with changing axis deviation.

Revelation of changing axis deviation at the end of atrial fibrillation without acute myocardial infarction

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. We present a case of revelation of changing axis deviation at the end of atrial fibrillation without acute myocardial infarction in a 74-year-old Italian man. Also this case focuses attention on changing axis deviation.

Right bundle branch block with revelation of changing axis deviation at the end of atrial fibrillation

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a left bundle branch block with changing QRS morphology and changing axis deviation. There are several possible explanations for the intermittent shift in the QRS axis in the presence of complete left bundle branch block. The most plausible explanation is the coexistence of left posterior hemiblock and predivisional left bundle branch block. Intermittent right axis deviation has been rarely reported in the presence of left bundle branch block also during atrial fibrillation and with acute myocardial infarction too. Isolated left posterior hemiblock is a very rare finding and transient right axis deviation associated with a left posterior hemiblock pattern has been also rarely described associated with acute myocardial infarction. Changing axis deviation with changing bundle branch block and new-onset of atrial fibrillation during acute myocardial infarction has been also reported. Changing axis deviation with intermittent right bundle branch block in a patient admitted with acute myocardial infarction has been also described. We present a case of a right bundle branch block with revelation of changing axis deviation at the end of atrial fibrillation in a 68-year-old Italian man.

Acute myocardial infarction and left bundle branch block with changing axis deviation

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Left bundle branch block is usually associated with normal or left axis deviation. Rarely the ECG shows a LBBB with changing QRS morphology and changing axis deviation. There are several possible explanations for the intermittent shift in the QRS axis in the presence of complete left bundle branch block. The most plausible explanation is the coexistence of left posterior hemiblock and predivisional left bundle branch block. We present a case of a left bundle branch block with changing axis deviation in a 93-year-old Italian woman admitted to the Cardiology Unit with an acute myocardial infarction.

Changing axis deviation during atrial fibrillation

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. We present a case of changing axis deviation during atrial fibrillation in a 63-year-old Italian woman. Also this case focuses attention on changing axis deviation.

Atrial flutter, ventricular tachycardia and changing axis deviation associated with scleroderma

Rhythm disturbances have been described in immunological and connective diseases. Scleroderma is a fibrotic condition characterized by immunological abnormalities, vascular injury and increased accumulation of extracellular matrix proteins. The heart is one of the major organs involved in scleroderma, the involvement of which can be manifested by myocardial disease, conduction system abnormalities, arrhythmias, or pericardial disease. Additionally, scleroderma renal crisis and pulmonary hypertension lead to significant cardiac dysfunction secondary to damage in the kidney and lung. Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. We present a case of atrial flutter, ventricular tachycardia and changing axis deviation in a 61-year-old Italian woman with scleroderma. This case focuses attention on changing axis deviation and on the presentation of arrhythmias in scleroderma. The underlying arrhythmogenic mechanisms are probably multiple and intriguing, even though the myocardial fibrosis and immunological autoantibody-mediated mechanisms seem to play a pivotal role.

Wellens' syndrome and other electrocardiographic changes in a patient with a left anterior descending artery subocclusion associated with a left main coronary artery subocclusion

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Patients with unstable angina have a higher incidence of left main coronary artery (LMCA) and proximal left anterior descending (LAD) coronary artery disease compared to patients with stable angina pectoris. In 1982, Wellens and colleagues described two electrocardiographic patterns that were predictive of critical narrowing of the proximal LAD artery, and were subsequently termed Wellens' syndrome. The criteria were: a) prior history of chest pain, b) little or no cardiac enzyme elevation, c) no pathologic precordial ST segment elevation, d) no loss of precordial R waves, and e) biphasic T waves in leads V2 and V3, or asymmetric, often deeply inverted T waves in leads V2 and V3. The ECG changes are best recognized outside the episode of anginal pain. Lead aVR and lead v1 ST segment elevation, during chest pain, has been reported in patients with LMCA disease with ST segment depression in leads V3, V4 and V5 (with maximal depression in V4).We present a case of changing axis deviation in a 37-year-old Italian man with a LAD coronary artery subocclusion associated with a LMCA subocclusion. This case focuses attention on the importance of the recognition of the patterns suspected for LAD coronary artery disease or for LMCA disease.

Changing axis deviation and acute myocardial infarction

Changing axis deviation has been rarely reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also rarely reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. We present a case of changing axis deviation in a 77-year-old Italian woman admitted to the Cardiology Unit with an acute myocardial infarction. Also this case focuses attention on changing axis deviation and acute myocardial infarction.

Atrial fibrillation associated with exogenous subclinical hyperthyroidism, changing axis deviation, troponin-I positive and without acute coronary syndrome

Changing axis deviation has been rarely reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also rarely reported during acute myocardial infarction associated with atrial fibrillation or at the end of atrial fibrillation during acute myocardial infarction. Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with coronary heart disease or mortality from cardiovascular causes but it is sufficient to induce arrhythmias including atrial fibrillation and atrial flutter. It has also been reported that increased factor X activity in patients with subclinical hyperthyroidism represents a potential hypercoagulable state. Serum troponin-I is a sensitive indicator of myocardial damage but abnormal troponin-I levels have been also reported without acute coronary syndrome and without cardiac damage. Abnormal troponin-I levels after supraventricular tachycardia have been also reported. We present a case of changing axis deviation in a 49-year-old Italian man with atrial fibrillation, exogenous subclinical hyperthyroidism and troponin-I positive without acute coronary syndrome. Also this case focuses attention on changing axis deviation, on subclinical hyperthyroidism and on the importance of a correct evaluation of abnormal troponin-I levels.

Revelation of changing axis deviation at the end of atrial fibrillation during acute myocardial infarction

It has been rarely reported changing axis deviation also during atrial fibrillation or atrial flutter. Changing axis deviation has been also rarely reported during acute myocardial infarction associated with atrial fibrillation too. We present a case of a 49-year-old Italian man with revelation of changing axis deviation at the end of atrial fibrillation during acute myocardial infarction. Also this case focuses attention on changing axis deviation.

Verification of pacemaker automatic mode switching for the detection of atrial fibrillation and atrial tachycardia with Holter recording

Verification of the accuracy of onset, offset, and duration of automatic mode switching (AMS) of pacemakers compared with onset and end of atrial fibrillation (AF) or atrial tachycardia (AT). Correct pacemaker diagnosis of atrial tachyarrhythmias (AA) is indispensable for reliable automatic prevention and intervention algorithms of AA. Comparison was made of the AMS registration of the pacemaker-stored electrograms (EGMs) and the number and cumulative duration of these episodes with continuous 7-day Holter monitoring. Atrial sensitivity was kept at 0.5 mV and far field R-wave recognition in the atrial channel was excluded by blanking of this signal. Lead types were confined to leads with short-ring tip spacing (10-13.8 mm). During Holter monitoring, 18 of 57 included patients with standard reason for pacemaker implantation showed episodes of AF or AT. Cumulative duration of AF and AT from Holter was correctly interpreted by the pacemaker in 99.9% of the patients. All episodes of AF, as seen on the Holter recording, were recognized by the pacemaker (correlation 99.9%). During AF, multiple episodes of undersensing were detected. The number of AMS episodes was influenced by undersensing during AF. The influence of these short episodes of undersensing on the total duration of AF was trivial (cumulative duration of AF was 99.9% correct). In patients with AT without AF on Holter (n=7) and in contrast to the AF episodes, the cumulative AT duration did not correlate well (63%) with the Holter recordings. The number of AMS episodes in the setting of AT was influenced by the atrial tachycardia detection rate setting and the duration of the post-ventricular atrial blanking interval. The total duration of AF is correctly represented by the total duration of AMS and can be considered a reliable measure of total AF duration. AT duration was poorly correlated with AMS duration. The number of mode switches does not reflect the number of episodes of AF/AT. Increased memory capacity allowing the storing of all EGMs triggered by the initiation of AF/AT would be the ideal setting with which to optimize the diagnostic performance of pacemakers.

On the mechanism of termination and perpetuation of atrial fibrillation

In an effort to further clarify the mechanism of termination and perpetuation of atrial fibrillation (AF), the intraatrial potentials during AF induced by programmable electrical stimulation were analyzed using the concept of wavelength which represents the size of a microreentrant circuit. Thirty patients with inducible AF were divided into 2 groups: 20 patients with AF that terminated spontaneously (group 1) and 10 patients with AF that did not terminate spontaneously (group 2). Wave-length is the product of refractory period and conduction velocity. During AF, the refractory period of the local atrial tissue was considered to correlate with the mean interval between each intraatrial potential (mean ff). An inverse relation was considered present between conduction velocity of the impulse and the width of intraatrial potentials (f width). Thus, the wavelength index was defined as (mean ff)/(mean f width). Ten intraatrial potentials at the high right atrium were sampled for measurement. Group 1 had higher wavelength indexes just after the induction of AF than did group 2 (1.33 ± 0.31 vs 1.10 ± 0.05, p < 0.05). In group 1, the wavelength indexes were increased from the initial value to 1.49 ± 0.36 just before termination of AF (p < 0.001). In 3 group 2 patients, AF stopped after disopyramide was administered intravenously, whereas the wavelength indexes at the end of AF were higher than those before drug administration (1.27 ± 0.08 vs 1.16 ± 0.04, p < 0.05). In conclusion, prolongation of the wavelength appears to be a major determinant for termination of AF, and shorter wavelengths are necessary for perpetuation of AF.