S64 ANAESTH, PAIN & INTENSIVE CARE; VOL 20(SUPPLEMENT) OCTOBER 2016 SPECIAL ARTICLE Peri-operative arrhythmias: diagnosis and management Syed Muhammad Nadeem, FCPS 1 , Imran Khan Sandeelo, FCPS 2 1 Consultant Department of Anesthesiology & In-charge Surgical Intensive Care Liaquat National Hospital & Medical College, Karachi (Pakistan) 2 Senior Registrar, Department of Cardiology, Liaquat National Hospital & Medical College, Karachi (Pakistan) Correspondence: Dr Syed Muhammad Nadeem, FCPS, Department of Anesthesiology & In-charge Surgical Intensive Care, Liaquat National Hospital National Stadium Road, Karachi 74800 (Pakistan); Phone: +92-21- 34412536, : +92-21-34412539; E-mail: smnadeemlnh@gmail.com ABSTRACT Arrhythmias are common during the perioperative period. These abnormal rhythms can alter the hemodynamics by reducing cardiac output and may contribute to an increase in morbidity and mortality. Early diagnosis and identification of correctable causes is essential for appropriate management of arrhythmias. Some of these arrhythmias are benign requiring no intervention, while others may need urgent therapeutic intervention. This article focuses on the diagnosis and management of arrhythmias in the perioperative setting. Key words: Rhythm disorders; Fibrillation; Heart block; Sinoatrial node; Bradycardia; Tachycardia. Citation: Nadeem SM, Sandeelo IK. Peri-operative arrhythmias: diagnosis and management. Anaesth Pain & Intensive Care. 2016;20 Suppl 1:S64-S76 Received: 9 August 2016; Reviewed: 12 July, 16 August, 20 August 2016; Corrected: 4 August, 19 August, 30 August; Accepted: 20 October 2016 INTRODUCTION The reported incidence of perioperative arrhythmias vary according to the nature of surgery, underlying co-morbidities and type of monitoring (continuous vs non-continuous) employed. It can be as high as 90% in patients with underlying structural heart disease undergoing cardiothoracic surgery with continuous monitoring (pre, intra and postoperative). 1,2 Majority of perioperative arrhythmias are supraventricular in origin with sinus tachycardia being the most common followed by atrial fibrillation as the most frequent in general surgical as well as cardio-thoracic surgery patients. 3,4 After atrial fibrillation, ventricular premature complexes (VPC) is the next commonly observed arrhythmia. 5 The arrhythmias can lead to an increase in perioperative morbidity and mortality. The tachyarrhythmias may cause hypotension by reducing cardiac output secondary to reduced diastolic filling time. The increase in heart rate increases myocardial oxygen demand. This increase in demand coupled with reduced supply due to hypotension may cause myocardial ischemia. Bradyarrhythmias may also cause a reduction in cardiac output in patients with a relatively fixed stroke volume. The loss of atrial contraction (atrial fibrillation) may reduce diastolic filling resulting in a marked increase in pulmonary venous pressures in patients with diastolic dysfunction. 2 In adults, the most effective combination of heart rate and ventricular filling time is approximately 100-110 beats/min. 6 Factors predisposing to perioperative arrhythmias Perioperative arrhythmias occur in patients with underlying heart disease (ischemic or valvular heart disease, cardiomyopathy, heart failure), electrolyte or acid-base disorder (hypokalemia, hyperkalemia, hypomagnesemia, hypercalcemia, acidosis), endocrine disorder (thyrotoxicosis, pheochromocytoma), intracranial bleed