Hamdan Medical Journal (previously the Journal of Medical Sciences)

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Heart Rate and QT Interval in Streptozotocin-induced Diabetic Rat

F C Howarth, E. Adeghate, M. Jacobson
Published in : Journal of Medical Sciences ; Vol 2, No 3 (2009)
DOI : 10.2174/1996327000902030108

Abstract


Aim: Prolonged QT interval is a common finding in diabetic patients. The effects of streptozotocin (STZ) – induced diabetes on QT interval has been investigated by application of 4 standard QT correction algorithms.

Methods: The electrocardiogram was recorded in STZ-treated (60 mg/kg bodyweight, ip) and agematched control rats with a biotelemetry system for the period of the study.

Results: Heart rate (HR) was significantly (P<0.01) reduced and QT interval was signifycantly (P<0.05) prolonged in diabetic rats compared to controls at 8, 10 and 12 weeks after STZ treatment. At 8 weeks HR was 260±16 BPM (n=5) in diabetic rats compared to 333±25 BPM (n=5) in controls and QT interval was 70±7 ms (n=5) in diabetic rats compared to 59±6 ms (n=5) in controls. When QT interval was corrected for HR there was no longer any significant difference in QT interval between diabetic and control rats. The effects of different correction techniques have been compared and the consequences considered.

Conclusion: The rapid and dramatic reductions in HR observed after administration of STZ are associated with a prolongation of the QT interval. However, the magnitude of the difference of the QT interval between the STZ and control groups was not significant after QT interval correction for the difference in HR.


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References


Julien J. Cardiac complications in non-insulindependent diabetes mellitus. J Diabetes Complicat 1997; 11:123-30.

Dhalla NS, Pierce GN, Innes IR, Beamish RE. Pathogenesis of cardiac dysfunction in diabetes mellitus. Can J Cardiol 1985; 1(4):263-81.

Casis O, Echevarria E. Diabetic cardiomyopathy: electromechanical cellular alterations. Curr Vasc Pharmacol 2004; 2(3):237-248.

Veglio M, Chinaglia A, Cavallo-Perin P. QT interval, cardiovascular risk factors and risk of death in diabetes. J Endocrinol Invest 2004; 27(2):175-81.

Takebayashi K, Sugita R, Tayama K, Aso Y, Takemura Y, Inukai T. The connection between QT dispersion and autonomic neuropathy in patients with type 2 diabetes. Exp Clin Endocrinol Diabetes 2003; 111(6):351-7.

Rana BS, Band MM, Ogston S, Morris AD, Pringle SD, Struthers AD. Relation of QT interval dispersion to the number of different cardiac abnormalities in diabetes mellitus. Am J Cardiol 2002; 90(5):483-7.

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. Diabetes Metab 2002; 28(2):127-32.

Veglio M, Bruno G, Borra M, et al. Prevalence of increased QT interval duration and dispersion in type 2 diabetic patients and its relationship with coronary heart disease: a population-based cohort. J Intern Med 2002; 251(4):317-24.

Veglio M, Chinaglia A, Cavallo PP. The clinical utility of QT interval assessment in diabetes. Diabetes Nutr Metab 2000; 13(6):356-65.

Kumhar MR, Agarwal TD, Singh VB, Kochar DK, Chadda VS. Cardiac autonomic neuropathy and its correlation with QTc dispersion in type 2 diabetes. Indian Heart J 2000; 52(4):421-6.

Veglio M, Giunti S, Stevens LK, Fuller JH, Perin PC. Prevalence of Q-T interval dispersion in type 1 diabetes and its relation with cardiac ischemia : the EURODIAB IDDM Complications Study Group. Diabetes Care 2002; 25(4):702-07.

Veglio M, Borra M, Stevens LK, Fuller JH, Perin PC. The relation between QTc interval prolongation and diabetic complications. The EURODIAB IDDM Complication Study Group. Diabetologia 1999; 42(1):68-75.

Rana BS, Lim PO, Naas AA, et al. QT interval abnormalities are often present at diagnosis in diabetes and are better predictors of cardiac death than ankle brachial pressure index and autonomic function tests. Heart 2005; 91(1):44-50.

Linnemann B, Janka HU. Prolonged QTc interval and elevated heart rate identify the type 2 diabetic patient at high risk for cardiovascular death. The Bremen Diabetes Study. Exp Clin Endocrinol Diabetes 2003; 111(4):215-22.

Christensen PK, Gall MA, Major-Pedersen A, et al. QTc interval length and QT dispersion as predictors of mortality in patients with non-insulin-dependent diabetes. Scand J Clin Lab Invest 2000; 60(4):323-32.

Robillon JF, Sadoul JL, Benmerabet S, Joly-Lemoine L, Fredenrich A, Canivet B. Assessment of cardiac arrhythmic risk in diabetic patients using QT dispersion abnormalities. Diabetes Metab 1999; 25(5):419-23.

Sawicki PT, Kiwitt S, Bender R, Berger M. The value of QT interval dispersion for identification of total mortality risk in non-insulin-dependent diabetes mellitus. J Intern Med 1998; 243(1):49-56.

Naas AA, Davidson NC, Thompson C, et al. QT and QTc dispersion are accurate predictors of cardiac death in newly diagnosed non-insulin dependent diabetes: cohort study. BMJ 1998; 316(7133):745-6.

Howarth FC, Jacobson M, Naseer O, Adeghate E. Short-term effects of streptozotocin-induced diabetes on the electrocardiogram, physical activity and body temperature in rats. Exp Physiol 2005; 90(2):237- 45.

Hosmane B, Locke C, Morris D. QT Interval: Correction for heart rate. J Appl Res 2006; 6(4): 288-99.

Ollerstam A, Persson AH, Visser SA, et al. A novel approach to data processing of the QT interval response in the conscious telemetered beagle dog. J Pharmacol Toxicol Methods 2007; 55(1):35-48.

Howarth FC, Jacobson M, Shafiullah M, Adeghate E. Effects of insulin treatment on heart rhythm, body temperature and physical activity in streptozotocininduced diabetic rat. Clin Exp Pharmacol Physiol 2006; 33(4):327-31.

Howarth FC, Al Sharhan R, Al Hammadi A, Qureshi MA. Effects of streptozotocin-induced diabetes on action potentials in the sinoatrial node compared with other regions of the rat heart. Mol Cell Biochem 2007; 300(1-2):39-46.

Lengyel C, Virag L, Kovacs PP, et al. Role of slow delayed rectifier K+-current in QT prolongation in the alloxan-induced diabetic rabbit heart. Acta Physiol (Oxf) 2008; 192(3):359-68.

Zhang Y, Xiao J, Lin H, et al. Ionic mechanisms underlying abnormal QT prolongation and the associated arrhythmias in diabetic rabbits: a role of rapid delayed rectifier K+ current. Cell Physiol Biochem 2007; 19(5-6):225-38.

Howarth FC, Jacobson M, Qureshi MA, et al. Altered gene expression may underlie prolonged duration of the QT interval and ventricular action potential in streptozotocin-induced diabetic rat heart. Mol Cell Biochem 2009.

Choi KM, Zhong Y, Hoit BD, et al. Defective intracellular Ca(2+) signaling contributes to cardiomyopathy in Type 1 diabetic rats. Am J Physiol 2002; 283(4):H1398-H1408.

Bracken NK, Woodall AJ, Howarth FC, Singh J. Voltage- dependence of contraction in streptozotocininduced diabetic myocytes. Mol Cell Biochem 2004; 261(1-2):235-43.





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