ISPUB.COM The Internet Journal of Third World Medicine Volume 7 Number 2 1 of 4 Orthodromic Atrioventricular Reentrant Tachycardia Presenting To The Komfo Anokye Teaching Hospital, Kumasi, Ghana I Owusu, A Bockarie, Y Amoako Citation I Owusu, A Bockarie, Y Amoako. Orthodromic Atrioventricular Reentrant Tachycardia Presenting To The Komfo Anokye Teaching Hospital, Kumasi, Ghana. The Internet Journal of Third World Medicine. 2008 Volume 7 Number 2. Abstract In Wolf-Parkinson-White (WPW) pattern pre-excitation, an accessory pathway known as the bundle of Kent conducts electric impulses directly from the atrial to the ventricles. Patients with WPW pre-excitation are therefore predisposed to paroxysmal supraventricular tachycardia (PSVT). The PSVT can be a narrow QRS complex tachycardia or broad QRS complex tachycardia. This presentation is on a patient with WPW pattern pre-excitation presenting as a narrow QRS complex tachycardia. INTRODUCTION The first publication on WPW syndrome was in 1930. Wolff, Parkinson and White reported 11 young healthy people with ECG syndrome of short PR interval, wide QRS and paroxysmal tachycardias 1 . Since that time, many studies have been done on WPW syndrome, and today we understand the pathogenesis and the mechanisms of the arrhythmias associated with it 2 , 3 , 4 . Patients with WPW syndrome have accessory pathway that conducts electrical impulses directly from the atrial to the ventricles. Ventricular activation results from both early activation (pre-excitation) of the ventricle and from normal activation. The degree of unopposed pre-excitation depends upon the time required to conduct through the right and left atria, the accessory pathway and the ventricular myocardium as compared to conduction through the normal pathways. This results in a QRS complex that is a fusion of ventricular pre-excitation and normal excitation, with a shorter PR interval, a small delta wave, and some prolongation of the QRS duration. Patients with WPW pattern pre-excitation are predisposed to recurrent atrioventricular reentrant tachycardia (AVRT). HISTORY A 53 year old woman, a widow with 3 children and a known hypertensive for 5 years, presented to the medical emergency unit, Komfo Anokye Teaching Hospital, Kumasi on 26th April 2008 with a history of recurrent palpitations and dizziness for two years. On the day of admission, she developed palpitations which progressively increased in severity. PHYSICAL EXAMINATION On physical examination, she looked ill, sweating, not dyspnoeic at rest and she had no pedal oedema. Her respiratory rate was 24 breaths/minute; the radial pulse was very rapid and thready. The systolic blood pressure was 60mmHg by palpation and the diastolic blood pressure was not recordable. The jugular venous pressure was not raised and the apex beat was at the 5 th left intercostals line in the mid-clavicular line. The heart sounds were normal and no murmurs were heard. The chest, abdomen and the central nervous system were also normal. INVESTIGATIONS An urgent 12-lead ECG was done (figure 1). It showed a heart rate of 222/minute, regular sinus rhythm, QRS complex duration of 61ms and repolarization abnormalities. Blood was taken for full blood count, blood urea nitrogen, serum creatinine, fasting blood glucose and serum lipid profile. Holter and echocardiography were also done; the results of these investigations are shown on table 1.