DOI: http://dx.doi.org/10.18203/2349-3933.ijam20195637

The evaluation of QTc prolongation and QT dispersion in type 2 diabetes mellitus as an indicator of cardiac autonomic neuropathy

Devinder Singh Mahajan, Hardeep Singh Deep, Navdeep Singh, Sukhjit Kaur

Abstract


Background: Diabetes mellitus refers to group of metabolic disorders characterized by hyperglycemia due to an absolute or relative deficit in insulin production or action. Diabetes mellitus produces pathological changes in most organs of the body including heart, blood vessels, kidneys, nerves and eyes. Cardiovascular autonomic neuropathy (CAN) is a severely debilitating yet underdiagnosed complication of diabetes. Diabetes-associated cardiovascular autonomic neuropathy damages autonomic nerve fibers that innervate the heart and blood vessels causing abnormalities in heart rate and vascular dynamics.

Methods: Total 80 cases of diabetes mellitus were selected. Cardiac autonomic neuropathy in them was diagnosed by a series of tests recommended by Ewing et al, which include - Valsalva ratio, Deep Breath Test, Heart rate response to standing, Postural Hypotension, SHGT Increase in diastolic BP on sustained hand grip. They were divided into 2 groups A and B depending on presence or absence of cardiac autonomic neuropathy. ECG was done to calculate QTc and QTd.

Results: In group A mean QTc was 0.344 sec and in group B in patients with mild CAN mean QTc was 0.432, moderate CAN mean QTc was 0.444, and in patients of severe CAN mean QTc was 0.481. p value was 0.001 that it is highly significant. Means more was degree of CAN more was prolongation of QT and similarly more the degree of CAN more was QTd.

Conclusions: Diagnosis of cardiac autonomic neuropathy by battery of cardiac autonomic function tests is a comlex procedure. The prolongation of QTc interval and more specifically QTd interval on ECG is a marker in diagnosis of cardiac autonomic neuropathy which can be easily evaluated.


Keywords


Cardiac autonomic neuropathy, Diabetes mellitus, QTc interval

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References


Powers AC. Diabetes Mellitus: Diagnosis, classification and pathophysiology. In: Kasper DL, Fauci AS, Hauser SL, Longo DL, Jameson JL, Loscalzo J, editors. Harrison’s Principles of Internal Medicine. 19th ed. New york: Mcgraw Hill Education; 2015;2399.

Forouhi NG, Wareham NJ. Epidemiology of diabetes. Med. 2010 Nov 1;38(11):602-6.

Keenan HA, Costacou T, Sun JK, Doria A, Cavellerano J, Coney J, et al. Clinical factors associated with resistance to microvascular complications in diabetic patients of extreme disease duration: the 50-year medalist study. Diabetes Care. 2007 Aug 1;30(8):1995-7.

Boyle PJ. Diabetes mellitus and macrovascular disease: mechanisms and mediators. Am J Med. 2007 Sep 1;120(9):S12-7.

Vinik AI, Erbas T, Casellini CM. Diabetic cardiac autonomic neuropathy, inflammation and cardiovascular disease. J Diabetes Investiga. 2013 Jan;4(1):4-18.

Maser RE, Lenhard JM, De Cherney SG. Cardiovascular autonomic neuropathy: the clinical significance of its determination. Endocrinol. 2000 Jan 1;10(1):27.

Pop-Busui R. Cardiac autonomic neuropathy in diabetes: a clinical perspective. Diabetes Care. 2010 Feb 1;33(2):434-41.

Ramasamy R, Vannucci SJ, Yan SS, Herold K, Yan SF, Schmidt AM. Advanced glycation end products and RAGE: a common thread in aging, diabetes, neurodegeneration, and inflammation. Glycobiol. 2005 Mar 10;15(7):16R-28R.

Vinik AI, Maser RE, Mitchell BD, Freeman R. Diabetic autonomic neuropathy. Diabetes Care. 2003 May 1;26(5):1553-79.

Selvaraj R. Basic Principles. In: Narsimhan C, Francis J, Schamroth C, editors. Leo Schamroth: An Introduction to electrocardiography. 8th ed. New Delhi: Wiley Publishers;2015:16-8.

Ahire C, Sarode V, Jadhav K, Shreeram V, Gaidhani N. Prevalence of cardiac autonomic neuropathy in short and long-standing type 2 diabetics in western Maharashtra. Int J Basic Appl Med Res. 2014;3:252-9.

Ninkovic VM, Ninkovic SM, Miloradovic V, Stanojevic D, Babic M, Giga V, et al. Prevalence and risk factors for prolonged QT interval and QT dispersion in patients with type 2 diabetes. Acta Diabetol. 2016 Oct 1;53(5):737-44.

Pop-Busui R. Cardiac autonomic neuropathy in diabetes: a clinical perspective. Diabetes Care. 2010 Feb 1;33(2):434-41.

Pillai JN, Madhavan S. Cardiac autonomic neuropathy and QTc interval in type 2 diabetes. Heart India. 2015 Jan 1;3(1):8.

Khoharo HK, Halepoto AW. QTc-interval, heart rate variability and postural hypotension as an indicator of cardiac autonomic neuropathy in type 2 diabetic patients. J Pak Med Assoc. 2012 Apr;62(4):328-31.

Takebayashi K, Aso Y, Sugita R, Takemura Y, Inukai T. Clinical usefulness of corrected QT intervals in diabetic autonomic neuropathy in patients with type 2 diabetes.2002;28:127-32.

Ewing DJ, Campbell IW, Clarke BF. The natural history of diabetic autonomic neuropathy. QJM: An Inter J Med. 1980 Jan 1;49(1):95-108.

Barthwal SP, Agarwal R, Khanna D, Kumar P. QTC prolongation in diabetes mellitus: an indicator of cardiac autonomic neuropathy. J Assoc Physic India. 1997;45(1):15-7.

Mathur C, Gupta D. QTc prolongation in diabetes mellitus: an indicator of cardiac autonomic neuropathy. J Indian Acad Clin Med. 2006;17:34-00.

Neki NS, Kaur J. A study of QTc prolongation and QT dispersion (QTd) as an indicator of cardiac autonomic neuropathy (CAN) in type 2 diabetes mellitus patients. J Int Med Sci Acad. 2014;27(4):195-6.

Malik M, Batchvarov VN. Measurement, interpretation and clinical potential of QT dispersion. J Am Coll Cardiol. 2000 Nov 15;36(6):1749-66.