Parkinson White Syndrome Research Articles

A Complex Presentation of Vestibular Paroxysmia in an Adolescent With Wolff- Parkinson-White Syndrome

Vestibular paroxysmia is an episodic vestibular disorder resulting from compression or irritation of the eighth cranial nerve. This disorder is a rare and difficult diagnosis in children. We report the case of a 16-year-old adolescent male with a history of syncope and coronavirus disease 2019 infection four months prior who presented with intermittent episodes of vertigo and unsteadiness several times a week. These events started abruptly, and he appeared frozen. However, he remained conscious and was able to answer questions. He subsequently resumed normal activity in less than a minute without seizure stigmata or postictal period. His general and neurological examinations were unremarkable. Extensive diagnostic evaluation yielded negative results, except for an electrocardiogram consistent with Wolff-Parkinson-White syndrome. However, his symptoms persisted after cardiac ablation, suggesting they were not related to this arrhythmia. Following unsuccessful trials with various medications, his symptoms resolved with carbamazepine. Early recognition and appropriate treatment of this condition could substantially improve the quality of life for affected individuals.

Neurological, Extracardiac, and Cardiac Manifestations of Ebstein's Anomaly Along With its Genetics, Diagnostic Techniques, Treatment Updates, and the Future Ahead.

Ebstein's anomaly is a congenital heart defect characterized by the displacement of the tricuspid valve, and its leaflets to be malformed. Due to the defect involving the tricuspid valve, there is a reverse flow of blood into the right-sided atrium, which may lead to cardiac hypertrophy and edema of the lower extremities. There is a decreased flow of blood out of the right heart due to reduced right ventricular contractility and tricuspid regurgitation. Children afflicted with thisanomaly usually suffer from atrial septal defect and this is usually diagnosed before birth on a routine ultrasound scan. In neonates, cyanosis can be seen due to right-to-left atrial shunting or as a result of severe congestive heart failure. If the infant has pulmonary hypertension, cyanosis is markedly increased as there will be a limitation in pulmonary blood flow. In adults, arrhythmias, cyanosis, and heart failure are seen. The bundle of Kent leads to the formation of an electrical conduction abnormality between the right ventricle and atrium. This leads to a condition commonly known as Wolff- Parkinson-White syndrome in patients. An enlarged spherical heart is usually present on a chest X-ray. ECG changes of Ebstein's anomaly show taller than usual P waves, PR prolongation, and right bundle branch block. There can be certain neurological and extracardiac manifestations too such as hemiplegia, stroke, dysarthria, etc. During fetal life, specifically at 16 and 20 weeks of gestation, the anomaly can be diagnosed via echocardiography. Prostaglandin infusion (PGE1) is given to maintain pulmonary circulation in neonates if cyanosis is seen. In children and adults with congestive cardiac failure due to this anomaly, medical management includes digoxin, beta-blockers, diuretics, and angiotensin converting enzyme (ACE) inhibitors to improve heart failure. Surgical treatment includes valve reconstruction. In this article, we review the pathophysiology, genetics, diagnosis, management, and prognosis of Ebstein's Anomaly along with a comprehensive discussion on its genetics, neurological manifestations, extracardiac features, and current advancements in treatment.

Abnormal electrocardiogram or echocardiogram as interim measures for CVD risk stratification in pregnancy and postpartum

Cardiovascular disease (CVD) is the leading cause of maternal mortality in the United States. The diagnosis of CVD is challenging as signs and symptoms of normal pregnancy may mimic CVD. The California Maternal Quality Care Collaborative (CMQCC) CVD risk assessment algorithm was used to help stratify pregnant and postpartum patients into low or high risk for CVD and guide further cardiac testing. We sought to evaluate the intermediate outcomes, i.e., abnormal electrocardiogram (EKG) and echocardiogram, as surrogates for CVD to assess the positive predictive value of the CMQCC tool in patients determined to be at high risk for CVD. Retrospective medical record review of 1,399 patients that underwent CVD risk stratification using the CMQCC algorithm over an 18-month period at a major hospital network in California. The primary outcome was the rate of abnormal EKG or echo, defined as abnormal cardiac structure and/or function, among patients who were determined to be at increased risk for CVD. Of 29 patients identified to be at increased risk, 20 received follow-up testing with EKG or echo within 60 days of the risk assessment. Over half (65%) of the patients were found to have underlying EKG or echo abnormality. Abnormal cardiovascular testing results included findings such as sinus tachycardia (HR > 100 bpm), conduction delays, Wolff Parkinson-White syndrome, left ventricular hypertrophy/diastolic dysfunction, and chamber dilation. Using these results as a surrogate for CVD, the CMQCC risk assessment tool identified 13 cases of previously undiagnosed cardiovascular dysfunction in the study population (Table 1). Use of the CMQCC CVD risk assessment tool provides an opportunity for early diagnosis of CVD that may allow for prompt clinical intervention in addition to patient education and promotion of healthy lifestyle changes. EKG and echo results may be used as intermediate outcomes to assess the positive predictive value of the tool. Future long-term studies should evaluate the benefits of obstetric CVD risk assessment on the prevention of CVD over the life course.

INITIAL ELECTROCARDIOGRAPHIC PROFILE OF THE POPULATION OF TANGIERS – MOROCCO INFECTED WITH SARS CoV2: ABOUT 1087 CASES

Abstract Introduction Coronavirus disease 2019 (COVID-19) is a pathology which initially affects the respiratory system, but also many other noble organs due to his inflammatory phase (Cytokine Storm), especially the cardiovascular system. The cardiovascular risk factors present in a population infected with SARS-COV 2 are of particular interest. The ECG is a fast available means to get an idea about the cardiac status. This permits not only to diagnose an unknown pre-existing pathology but also to detect a killing cardiac complication of the SARS COV-2 infection. Methods We performed a cross-sectional study on COVID-19 patients passing through Tangiers sorting center. Clinical characteristics and ECG variables were manually abstracted from the electronic health record and first ECG. Our aim was to describe the electrocardiographic features of Covid-19 Patients in Morocco. Results 1087 patients who presented to the COVID 19 triage center in Tangier-Morocco were systematically given a pre-treatment ECG before deciding on the type of management: outpatient, ward, intensive care.The mean age was 42.78 years, 30.5% of the cases had at least one cardiovascular risk factor, 8.6% of the patients were followed for hypertension, 8.2% for type 1 or 2 diabetes, 10.9% of the patients were obese with a BMI greater than 30, and 26.4% of the patients were either men over 50 or women over 60. The mean heart rate was 80.89 bpm ± 15.58; The mean PR interval was 149.51 ± 21.70; The mean QRS duration was 98.59 ms ± 11.71; The mean QTc interval was 406.62 ms ± 24.32. We found: A conduction disorder in 11.1% of patients, 1.6% of 1st degree BAV, 2 of incomplete right bundle branch block, 5.7% of complete BBD, 0.9% of BBG and 1.4% of left anterior hemiblock. A rhythm disorder in 5.1% of our patients, 2.1% of ventricular extrasystole, 1.6% of supraventricular extrasystole, 1.1% of atrial fibrillation, wolf- parkinson-white syndrome in 0.3% of patients and 0.5% of Brugada pattern. A repolarization disorder in 5.2% of our population. 3.6% of patients had negative T waves and 1.6% had ST segment abnormalities. We also found a significant association between the presence of cardiovascular risk factors and electrical abnormality. Conclusion We found that the majority of EKG were normal and all critically ill patients had a large spectrum of EKG abnormalities. Pending the results, we still believe that we can potentially establish a severity score including EKG to predict inpatient mortality in Moroccan covid-19 patients. Additional Content An author video to accompany this abstract is available on https://academic.oup.com/eurheartjsupp. Please click on the arrow next to ‘More Content’ and then click on ‘Author videos’.

Perioperative management of Wolff–Parkinson-White syndrome – A case series

Wolff-Parkinson-White (WPW) syndrome is a type of pre-excitation syndromewhere part of cardiac ventricles are activated too early by virtue of an accessory pathway, that directly attaches atria and ventricles, thereby allowing electrical activity to bypass AV node, thus leading to episodes of tachycardia which can be either asymptomatic or may present with dyspnoea on exertion or with palpitation. As it’s a rare condition, we report 3 cases of WPW Syndrome which adds more evidence to the current literature. The anaesthetic management can be challenging and has to be customized to the nature of the surgery and the patient to avoid life-threatening tachyarrhythmias. Perioperative management of WPW syndrome is challenging and requires good pre-operative planning and adequate preparation for intraoperative and post-operative period.

Редкий случай развития инфаркта миокарда 2-го типа у пациента с синдромом Вольф-Паркинсон-Уайта

Currently, myocardial infarction diagnostics has no diffi culties. Type 2 myocardial infarction is an exception, as it occurs due to a mismatch with oxygen delivery along coronary arteries and myocardial demand for it. Th e disease is secondary and this is the main diffi culty for its diagnostics. The article described a case of a young man having Wolff -Parkinson-White syndrome with type 2 myocardial infarction development. The main cause of myocardial necrosis is a prolonged paroxysm of reciprocal atrioventricular antidromic tachycardia.

Atrial Fibrillation Associated with Wolf-Parkinson-White Syndrome in Patients with Brugada Syndrome: A Review

The Brugada syndrome is an autosomal dominant rare form of cardiac arrhythmia and has been associated with high risk of sudden cardiac death predominantly in younger male patients. It is associated with polymorphic ventricular arrhythmia/ventricular fibrillation, Supraventricular arrhythmia mainly atrial fibrillations and Wolf- Parkinson white syndrome. Patients can be presented with symptom like syncope, palpitation, sudden cardiac death and asymptomatically. Several pathogenic genes have been identified as associated with the disease but SCN5A is the most prevalent one. Several genetic mutations of different subunits of sodium, calcium and potassium channel have been involved. The management of Brugada syndrome and Wolf-Parkinson-White syndrome in patients with atrial fibrillation should be generally includes implantable cardioverter defibrillator and Radiofrequency catheter ablations. This brief review focuses on recent clinical diagnosis, genetic basis and advances in pharmacological treatment of Brugada syndromes with atrial fibrillation and wolf-Parkinson white syndrome.

The Case of Flecainide Toxicity: What to Look For and How to Treat

Introduction: Flecainide is a class Ic antiarrhythmic agent used to prevent and treat both ventricular and supraventricular tachycardias including atrial fibrillation, AV nodal re-entrant tachycardia (AVNRT), and Wolff- Parkinson-White syndrome (WPW). Flecainide can cause serious side effects include cardiac arrest, arrhythmias, and heart failure. Despite its growing use, the presenting signs and symptoms of flecainide toxicity are not familiar to most clinicians. Case description: This was a 58 year-old female who presented from her skilled nursing facility due to hypoxia and altered mental status. Past medical history was notable for paroxysmal atrial fibrillation for which she was on flecainide. At the nursing facility the patient was noted to be obtunded, whereas at baseline she was reportedly alert and oriented. On presentation to the Emergency Department EKG demonstrated wide-complex tachycardia. Subsequent lab results were notable for hypokalemia and an acute kidney injury (AKI). A repeat EKG was concerning for ischemia in leads II, III, aVF and cardiology was emergently consulted. They noted the EKG changes were consistent with flecainide toxicity, specifically a prolonged PR interval and QRS. She was eventually admitted to the medical intensive care unit. Her wide complex tachycardia on admission was ultimately attributed to flecainide toxicity in setting of AKI. Six days after presentation, it was found that her flecainide level was in the toxic range at 2.02 ug/mL (normal range: 0.20-1.00 ug/mL, toxic>1.50 ug/mL). Discussion: Flecainide intoxication is rare but serious due to the potential for cardiogenic shock. Its diagnosis can be difficult as the flecainide serum level may take days to result and there are no pathognomonic clinical signs. This case demonstrates the necessity of keeping flecainide toxicity on the physician’s differential for patients who are taking the drug, as well as what ECG and laboratory findings can suggest it as the etiology. A heightened suspicion is warranted in the patient with new renal impairment. Treatment can be lifesaving if initiated promptly.

Analiza rozpoznań elektrokardiograficznych u dzieci z nieprawidłowym wynikiem przesiewowego EKG wykonanego w szkole

Introduction. Electrocardiography (ECG) is one of the fundamental procedures used as a diagnostic tool in pediatric cardiology. ECG is indispensable in the evaluation of children with arrhythmias, some of which like in long QT syndrome and Wolff- Parkinson-White (WPW) syndrome could be life threatening. Aim. The aim of the study was to analyze diagnostic tests of the cardiovascular system in children with abnormal ECG screening performed at school. Material and methods. Abnormal ECG screening in 31 children, aged 7-13 years old (average 10.6 years) was re-analyzed. In all 31 children referred to pediatric cardiology department ECG and echocardiogram were performed. In case of arrhythmia suspicion, 24-hour Holter ECG monitoring and exercise test were also done. Results. Based on ECG screening performed at school, initially in 22 out of the 31 children significant changes in ECG were found and minor in 9. After verification in the pediatric cardiology department 50% of children with previously diagnosed significant changes in ECG were considered to have a normal ECG. Only in 2 children pathology was confirmed (WPW syndrome and QT prolongation). The most frequent falsely diagnoses in ECG included: hypertrophy of the left ventricle, heart axis deviation, nonspecific repolarization changes, partial right bundle branch block. Conclusions. 1. The interpretation of the ECG in children requires taking into account the age differences and should be carried out by a pediatric cardiologist. 2. Most of the changes found in screening ECG in children were irrelevant without clinical significance.

A decade of catheter ablation of cardiac arrhythmias in Sweden: ablation practices and outcomes.

AimsCatheter ablation is considered the treatment of choice for many tachyarrhythmias, but convincing ‘real-world’ data on efficacy and safety are lacking. Using Swedish national registry data, the ablation spectrum, procedural characteristics, as well as ablation efficacy and reported adverse events are reported.Methods and ResultsConsecutive patients (≥18 years of age) undergoing catheter ablation in Sweden between 01 January 2006 and 31 December 2015 were included in the study. Follow-up (repeat ablation and vital status) was collected through 31 December 2016. A total of 26 642 patients (57 ± 15 years, 62% men), undergoing a total of 34 428 ablation procedures were included in the study. In total, 4034 accessory pathway/Wolff–Parkinson–White syndrome (12%), 7358 AV-nodal re-entrant tachycardia (21%), 1813 atrial tachycardia (5.2%), 5481 typical atrial flutter (16%), 11 916 atrial fibrillation (AF, 35%), 2415 AV-nodal (7.0%), 581 premature ventricular contraction (PVC, 1.7%), and 964 ventricular tachycardia (VT) ablations (2.8%) were performed. Median follow-up time was 4.7 years (interquartile range 2.7–7.0). The spectrum of treated arrhythmias changed over time, with a gradual increase in AF, VT, and PVC ablation (P < 0.001). Decreasing procedural times and utilization of fluoroscopy with time, were seen for all arrhythmia types. The rates of repeat ablation differed between ablation types, with the highest repeat ablation seen in AF (41% within 3 years). The rate of reported adverse events was low (n = 595, 1.7%). Death in the immediate period following ablation was rare (n = 116, 0.34%). ConclusionCatheter ablations have shifted towards more complex procedures over the past decade. Fluoroscopy time has markedly decreased and the efficacy of catheter ablation seems to improve for AF.

Commentary: An Unusual Case of Leadless Pacemaker Implantation in a Patient with Wolff–Parkinson-White Syndrome: Just Because We Can, Does That Mean That We Should?

Commentary: An Unusual Case of Leadless Pacemaker Implantation in a Patient with Wolff–Parkinson-White Syndrome: Just Because We Can, Does That Mean That We Should?

Radiofrequency Ablation of Cardiac Arrhythmias

Radiofrequency ablation is a curative procedure for paroxysmal supraventricular tachycardias (PSVT, also known as PAT). The success rate is over 90%, and the complication rate is very low. Patients requiring long term drug treatment, and patients with PSVT and Wolff- Parkinson White syndrome on ECG, should be considered for this procedure. It is cost effective and improves quality of life. Atrioventricular nodal ablation and permanent pacemaker implantation is effective in heart rate control in patients with drug refractory paroxysmal or permanent atrial fibrillation. This procedure does not alter the requirement for anticoagulation. Atrial flutter responds well to radiofrequency ablation, as do many atrial tachycardias and idiopathic ventricular tachycardias. (author abstract)

Left lateral free wall pathway ablation complicated by plaque rupture and acute occlusion of the left anterior descending coronary artery

Radiofrequency (RF) ablation of accessory bypass tracts associated with the Wolff -Parkinson-White (WPW) syndrome has become the treatment of choice for many arrhythmias. Complications are unusual and acute coronary artery occlusion is very rare. We here present a 38-year-old male patient with an acute occlusion of proximal left anterior descending (LAD) coronary artery after RF ablation of a left free wall accessory pathway. An interesting feature is the site of the coronary artery occlusion which is remote from the RF application site. The occlusion was successfully treated with the placement of an intracoronary stent.

臨床 WPW症候群における副伝導路(Kent束)の不応期測定について

臨床 WPW症候群における副伝導路(Kent束)の不応期測定について

Adult congenital heart disease (grown-up congenital heart disease)

Congenital heart disease (CHD) may be defined as a structural abnormality of the heart or intrathoracic great vessels that is present at birth and is, or may become, of functional significance. This definition excludes congenital cardiomyopathies and arrhythmias such as Wolff– Parkinson–White syndrome even if they are due to abnormalities present at birth. CHD affects around 7.6 in every 1000 live births in the UK amounting to 5000 babies each year. Of these, 60% are diagnosed in infancy, 30% in childhood, and 10% as adults (particularly secundum atrial septal defect, Ebstein’s anomaly, coarctation of the aorta, and congenitally corrected transposition). The majority of patients with CHD are amenable to treatment by either device closure or surgery, and 90% of these children now survive to adulthood. Current estimates suggest that there are 1.2 million adults in Europe and a further 2 million in the USA with adult CHD (ACHD). In 2010, it was estimated that there were 200 000 people aged 16 and over with ACHD in the UK. Of these, 20–25% require life-long specialist care, 35–40% require access to expert consultation, and the remaining 40% need little ongoing support.

Wolf-Parkinson-White syndrome in young men presenting with palpitation: the pattern of delta waves in predicting location of accessory pathway

Palpitation is a common presenting symptom in the emergency department. Wolf-Parkinson White (WPW) syndrome is a cardiac conduction disorder that may present with palpitation and lead to sudden cardiac death. WPW could be detected by electrocardiogram (ECG). In this case report, we present two young male patients with WPW syndrome admitted to our hospital with history of repeated and progressive palpitation. ECG of the first patient revealed supraventricular tachycardia which converted to sinus rhythm after propanolol treatment. ECG showed sinus rhythm with delta wave in lead II,III,aVF, V1 suggesting the presence of accessory pathway (AP) in left lateral wall. Electrophysiology study confirmed the presence of AP and radio frequency catheter ablation was successfully done resulted in disappearance of delta on outpatient clinic ECG. Patient has no symptom and he do not have to take medication. ECG of the second patient revealed supraventricular tachycardia with abberancy. After amiodarone infusion, ECG showed sinus rhythm with delta wave in lead I,II,aVL suggesting the presence of accessory pathway in anteroseptal wall. Electrophysiology study and catheter ablation did not perform for this patient because of financial problem, however amidarone has to be taken regularly to prevent the recurrence of supraventricular tachycardia. (Med J Indones 2011; 20:298-301)Keywords: ECG, palpitation, supraventricular tachycardia, Wolf- Parkinson White syndrome

Acupuncture treatment for cardiac arrhythmias: A systematic review of randomized controlled trials

Cardiac arrhythmias are common [1]. The clinical manifestations range from self-limited benign discomfort, such as palpitations, to lifethreatening crisis [1]. Traditional Chinese medicine (TCM) advocate several treatment options for cardiac arrhythmias [2]. Recent scientific experimental studies suggest that acupuncture might be an effective intervention for cardiac arrhythmias through multiple mechanisms [3]. The aim of this systematic review is to critically evaluate the clinical evidence for or against the notion that acupuncture is an effective treatment for arrhythmias through the explicit searching regardless of language. The following electronic databases and registry of clinical trials were searched from their inception through October 2010: MEDLINE, CINAHL, AMED, the Cochrane library, CNKI, J-East, Korean Studies Information, DBPIA, KoreaMed, KISTI, KMbase, NDSL and WHO International Clinical Trials and clinicaltrials.gov registries. The searching strategy was as follows: acupuncture AND (cardiac arrhythmia OR sinus arrhythmia OR atrial fibrillation OR bradycardia OR atrial premature complexes OR ventricular premature complexes OR heart block OR sick sinus syndrome OR Wolff– Parkinson–White syndrome OR tachycardia OR ventricular fibrillation OR ventricular flutter). The bibliographies of the included articles were also searched for relevant studies. No restrictions were applied according to language or publication status. Only randomized and quasi-randomized controlled trials were included. Hard copies of all of the relevant articles were read, and the data were extracted by two of the authors (THK, TYC). The quality of the selected studies was assessed according to the Cochrane criteria [4]. The Cochrane collaboration's software was used for the metaanalysis (the Nordic Cochrane Centre). In total 571 potentially relevant articles were identified, 10 of which met the inclusion criteria (Fig. 1). Three studies assessed the effectiveness of the acupuncture for paroxysmal supraventricular tachycardia (PSVT) [5–7]. Two of three studies assessed the immediate effect on heart rate after one acupuncture treatment [5,6]. The results of meta-analysis did not demonstrate a statistically significant difference compared with conventional drug therapy (n=59; RR, 0.90, 95% CIs 0.73 to 1.11; I=0%) (Fig. 2A) [5,6]. The third study tested the long term treatment effect of acupuncture in PSVT patients and acupuncture generated a favorable effect on the conversion of a normal sinus rhythm (NSR) compared with medication for PSVT [7]. Three studies tested the effectiveness of acupuncture compared with the oral administration of anti-arrhythmics for the treatment of ventricular premature beat (VPB) [8–10]. The results of the metaanalysis of these three RCTs failed to reveal significant effects of acupuncture treatment on the response rate compared with antiarrhythmics (n=140; RR, 1.12, 95% CIs 0.94 to 1.35; I=42%) (Fig. 2B) [8–10]. Two RCTs tested the effects of acupuncture on atrial fibrillation (Af) [11,12]. There were significant differences in favor of acupuncture treatment in both studies [11,12]. One RCT [13] assessed the effect of a single acupuncture in patients with sinus tachycardia (ST) and showed significant effects for reducing heart rate. The other RCT [14] investigated the effects of acupuncture on patients with ventricular extrasytole (VE). The results showed significant effects of acupuncture on alleviating symptoms and reducing the number of premature beats. Adverse events (AEs) werementioned in only two of the trials and no AEs were noted in the acupuncture group [12,13] (Table 1). We explored the clinical evidence for or against acupuncture as a treatment of various types of cardiac arrhythmias. Several studies demonstrated that acupuncture may be an effective treatment of cardiac arrhythmias. However, the evidence associated with acupuncture treatment for cardiac arrhythmias is limited because the majority of the studies were of low methodological quality [15]. The paucity of rigorous RCTs and their small sample sizes is a serious limitation of the evidence.

Cryoablation par cathéter des tachycardies : principes et indications

Cryoablation is used for definitive treatment of arrhythmias by catheter after a 4 min application of a -70 degrees C temperature. There are three main indications of this technique: (1) the treatment for intranodal tachycardia is commonly performed using cryoablation. Success rates are high with no atrio-ventricular block (AVB) risk, (2) the ablation of atrioventricular accessory pathways (Wolf Parkinson-White syndrome), close to His-bundle has a high success rate; the use of a cryo focal catheter avoid AVB risk, (3) the ablation of pulmonary vein potentials with a cryo-balloon in the left atrium for atrial fibrillation. The success rate is high, similar to that achieved with radiofrequency ablation. The cryoballoon procedure is easier to perform because ablation is done in a single step, with a circular application and not point by point. It is well tolerated because it is less painful. There is no risk of pulmonary vein stenosis or esophagus injury. It is less thrombogenic.

Pre-excitation pattern associated with accessory pathway related tachycardia: Case report

Pre-excitation is based on an accessory conduction pathway between the atrium and ventricle. The term Wolff-Parkinson-White (WPW) syndrome is used for patients with the pre-excitation/WPW pattern associated with AP-related tachycardia. We present a 52-year-old man with severe palpitation, fatigue, lightheadedness and difficulty breathing. The initial ECG showed tachyarrhythmia with heart rate between 240 and 300/min. He was treated with antiarrhythmics (Digitalis, Verapamil, Lidocaine) with no response. Then, the patient was treated with electrical cardioversion and was referred to our Clinic for further evaluation with the diagnosis: "Ventricular tachycardia". During in-hospital stay, the previously undiagnosed WPW pattern had been seen. Additional diagnostic tests confirmed permanent pre-excitation pattern (ECG Holter recording, exercises test). The patient was referred to an electrophysiologist for further evaluation. Mapping techniques provided an accurate assessment of the position of the accessory pathway which was left lateral. The elimination of the accessory pathway by radiofrequent catheter ablation is highly effective in termination and elimination of tacchyarrhythmias. Symptomatic, life-threatening arrhythmia, first considered as ventricular tachycardia, reflected atrial fibrillation with ventricular pre-excitation over an accessory pathway in a patient with previously undiagnosed WPW syndrome.

Mechanisms for the genesis of paroxysmal atrial fibrillation in the Wolff--Parkinson--White syndrome: intrinsic atrial muscle vulnerability vs. electrophysiological properties of the accessory pathway

Paroxysmal atrial fibrillation (PAF) develops in up to one-third of patients with the Wolff Parkinson-White syndrome (WPW). The reason for this high incidence of PAF in the WPW syndrome is not yet clearly understood. When PAF appears in patients with WPW syndrome who have anterograde conduction via the accessory pathway (AP), it may be life-threatening if an extremely rapid ventricular response develops degenerating into ventricular fibrillation. Several mechanisms responsible for the genesis of PAF in WPW patients were hypothesized, namely, spontaneous degeneration of atrioventricular reciprocating tachycardia into atrial fibrillation (AF), electrical properties of the APs, effects of APs on atrial architecture, and intrinsic atrial muscle vulnerability. Focal activity, multiple reentrant wavelets, and macroreentry have all been implicated in AF, perhaps under the further influence of the autonomic nervous system. AF can also be initiated by ectopic beats originating from the pulmonary veins, and elsewhere. Several studies demonstrated a decrease incidence of PAF after successful elimination of the AP, suggesting that the AP itself may play an important role in the initiation of PAF. However, PAF still occurs in some patients with the WPW syndrome even after successful elimination of the AP. There is an important evidence of an underlying atrial disease in patients with the WPW syndrome. Atrial vulnerability has been studied performing an atrial endocardial catheter mapping and analysing abnormal atrial electrograms. Other studies evaluated atrial refractoriness and intraatrial conduction times, suggesting an intrinsic atrial vulnerability as the mechanism of PAF and considering the AP as an innocent bystander. It is our intention to analyse the available data on this particular and interesting topic since AF has a singular prognostic significance in patients with the WPW syndrome, and its incidence is unusually high in the absence of any clinical evidence of cardiac organic disease.