Page 274 - fbkCardioDiabetes_2017

250 Cardio Diabetes Medicine 2017

Diabetic Dysrhythmias

Dr. Ulhas Pandurangi

Chief: Dept of Cardiac Electrophysiology and Pacing
Arrhythmia-Heart Failure Academy Madras Medical Mission

Abstract DM is recognized as a major cardiovascular risk
Diabetes mellitus (DM) is the leading cause of car- factor and its close relationship with cardiovascular
1
diovascular diseases. It is one of the strongest and morbidity and mortality is well established . Although
independent risk factors for cardiovascular morbidi- coronary artery disease and related cardiac events
ty and mortality. The accelerated atherosclerosis in are the most documented diabetic cardiovascular
large arteries and typically in coronary arteries lead complications, cardiac electrical system is also an
to ischemic heart disease (IHD) at an early age with important target for diabetic damage. DM is estab-
more severe sequel. Metabolic abnormalities may lished as an independent risk factor for AF, VA, SCD
2,3
lead to cardiomyopathy. The increased prevalence and bradyarrhythmias . There has been growing evi-
of IHD and cardiomyopathy leads to increased inci- dence about the relationship between hypoglycaemic
4,5
dence of cardiac arrhythmias especially atrial fibril- episodes and ventricular rhythm disorders . The re-
lation (AF) and ventricular tachyarrhythmia (VA). Di- lationship between DM and arrhythmic disorders is
abetic cardiac autonomic neuropathy (DCAN) is in- not fully understood. This article is on overview of
creasingly recognised as the cause of more frequent etiopathogenesis and management diabetic dys-
paroxysmal AF episodes and their conversion into rhythmias.
persistent forms. The increased incidence of sudden
cardiac death (SCD) due to VA is attributed to a large Diabetes and AF
extent to DCAN. The increased susceptibility to AF is the most common arrhythmia in clinical practice
resulting in major cardiovascular morbidity and mor-
postural hypotension and syncopal episodes are the 6
result of DCAN. The tolerance level of DCAN patients tality . Earlier The Framingham Study and recently a
7
specifically and DM patients in general towards the study from Movahed et al clearly established that
episodes of more common regular supraventricular DM is a powerful and independent risk factor for the
tachycardias may be lower. Acute changes in met- development of AF. Although there is no single and
abolic profile during ketoacidosis episodes might easy explanation, the electrical and anatomical re-
trigger arrhythmias. modelling atria and increasing incidence of IHD and
cardiomyopathy in DM seem to be reasons for AF.
In the absence of specific therapy for diabetic dys- Fibrosis in the atrial tissue is the anatomical hallmark
rhythmias general measures including antiarrhythmic of AF with a role in both starting and perpetuation of
drugs, radio frequency ablation (RFA) and devices the arrhythmia and as the fibrosis expands it is more
such as pacemakers and defibrillators are empiri- likely that paroxysmal AF transforms into permanent
cally used. Hypoglycaemia can be a potential trigger or anti arrhythmic resistant type. Kato et al showed
8
for arrhythmias and sugar control needs meticulous that DM related atrial fibrosis has a potential role in
monitoring. Sinus node dysfunction and degenera- starting AF in diabetic rat models. Exaggerated sys-
tion of conduction system leading to symptomatic temic and tissue level oxidative stress seems to be
bradycardia is more common in DM. The implanted the key element in atrial fibrosis related to DM.
devices are more prone for infections.
Non enzymatic glycosylation of proteins and the end
Introduction products of this pathway (Advanced Glycation End

GCDC 2017