1. Clinical Symptoms of Atrial Fibrillation according to QTc Interval Duration Kulik V.L., Yabluchansky N.I. Medical Clinics Chair National University of Karazin (Kharkov, Ukraine)

2. Causes for the Investigation QT shortening, less than 358 ms, or its prolongation, more than 437 ms, relate to a high risk of AF development and sudden cardiac death. QT shortening, less than 358 ms, or its prolongation, more than 437 ms, relate to a high risk of AF development and sudden cardiac death. The patients with congenital short QT syndrome (2nd genotype) have a high risk of developing AF. The patients with congenital short QT syndrome (2nd genotype) have a high risk of developing AF. There are no studies dedicated to the topic of the relationship between QTc and AF clinical symptoms. There are no studies dedicated to the topic of the relationship between QTc and AF clinical symptoms.

3. Objective of the Study To study the relationship between adjusted QT interval and clinical symptoms in patients with AF, with the goal of improving the quality of the diagnosis and management of this arrhythmia. To study the relationship between adjusted QT interval and clinical symptoms in patients with AF, with the goal of improving the quality of the diagnosis and management of this arrhythmia.

4. Investigated Population 98 patients (67 men and 31 women), age 64 ± 10 years old. Time of evolution of AF: 6.5±5 years old Causes of AF: CAD (36 patients) CAD (36 patients) HBP (83 patients) HBP (83 patients) CAD and HBP (32 patients) CAD and HBP (32 patients) The relationship between the forms of AF (paroxysmal, persistent, chronic) was 1:4:11, respectively.

5. Investigated Population Classification according the characteristics of the patients Gender Gender - male - male - female - female Age: – adults (men 45-60 years old, women 45-55 years old) Age: – adults (men 45-60 years old, women 45-55 years old) - older adults (men 61-74 y.o., women 56-74 y.o.) - older adults (men 61-74 y.o., women 56-74 y.o.) - elderly (men and women 75-87 y.o.) - elderly (men and women 75-87 y.o.) AF characteristics AF characteristics –Time of evolution (up to 10 years or more than 10 years) –Form (chronic, persistent, paroxysmal) –Classification by HR (bpm) - bradi- (less than 60), normo- (60-90) and tachycardia (more than 90) Degree of HF (FC І-ІІІ) Degree of HF (FC І-ІІІ) LV Ejection Fraction (EF) (20-43%, 44-66% and 67-88%) LV Ejection Fraction (EF) (20-43%, 44-66% and 67-88%) Stable chronic angina (FC І-ІІІ) Stable chronic angina (FC І-ІІІ) Systolic and diastolic pressure: normal BP – below 140/90 mm.Hg. Systolic and diastolic pressure: normal BP – below 140/90 mm.Hg. - mild HBP (systolic pressure 140-159 mm.Hg., diastolic pressure 90-99 mm.Hg.) - mild HBP (systolic pressure 140-159 mm.Hg., diastolic pressure 90-99 mm.Hg.) - moderate HBP (syst. pres.160-179 mm.Hg., diast. pres. 100-109 mm.Hg.) - moderate HBP (syst. pres.160-179 mm.Hg., diast. pres. 100-109 mm.Hg.) - severe HBP (syst. pres. more than 180 mm.Hg., diast. pres. more than 110 mm.Hg.) - severe HBP (syst. pres. more than 180 mm.Hg., diast. pres. more than 110 mm.Hg.) History of AMI History of AMI History of stroke History of stroke

6. Investigated Population Inclusion and exclusion criteria Inclusion criteria: AF AF CAD (CSA FC I-III) CAD (CSA FC I-III) HBP HBP Endocarditis, myocarditis, pericarditis Endocarditis, myocarditis, pericarditis Valve diseases Valve diseases Extrasystole Extrasystole Conduction disorders Conduction disorders Chronic heart failure (FC I-III) Chronic heart failure (FC I-III) Exclusion criteria: Chronic stable angina, FC IV Chronic stable angina, FC IV Acute coronary syndromes Acute coronary syndromes Heart failure FC IV Heart failure FC IV

7. Equipment Used and Evaluated Parameters “CardioLab+” computerized electrocardiograph Evaluated parameters: QT interval (ms) QT interval (ms) HR (bpm) HR (bpm) “Sim 5000 plus” echocardiograph Evaluated parameters: LVEF (%) LVEF (%) “Microlife” manual blood pressure cuff Systolic pressure (mm.Hg.) Systolic pressure (mm.Hg.) Diastolic pressure (mm.Hg.) Diastolic pressure (mm.Hg.)

8. Measurement and Standardization Method for the QT Interval The measurement of QT duration in 3 consecutive complexes since the onset of the Q wave up to the end of T wave, in the DII, V5 and V6 leads, choosing the longest QT. The measurement of QT duration in 3 consecutive complexes since the onset of the Q wave up to the end of T wave, in the DII, V5 and V6 leads, choosing the longest QT. QTc estimation: QTc estimation: QTс = QT + 0.154×(1000 − RR) This formula was used in the Framingham study in patients with AF* * - Sagie A, Larson MG, Goldberg RJ, Bengston JR, Levy D. "An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study)". Am J Cardiol 70 (7): 797–801, 1992.

9. Classification of QTc Duration Classification of QTc duration: Classification of QTc duration: –Short (less than 320 ms) –Normal (320-440 ms) –Long(more than 440 ms) QTc interval divided each 30 ms QTc interval divided each 30 ms

10. Statistical Analysis Data base in Microsoft Excel Data base in Microsoft Excel Statistical analysis with parametric methods Statistical analysis with parametric methods Construction of graphs on QTc duration in different subsets Construction of graphs on QTc duration in different subsets

11. Distribution of QTc Duration between Patients Most patients are in a range between 381 and 470 ms. The most frequent QTc duration was 381-410 ms. More than a third of the patients have prolonged QTc.

12. Ratio between QTc and Gender The ratio between men and women was 2:1. The QTc duration range in men was greater than in women. The ratio between the 381-410 and 441- 470 ms intervals between men and women was similar.

13. Ratio between QTc and the Age of Men With age, the QTc dispersion range shifts toward higher values.

14. Ratio between QTc and the Age of Women With age, the QTc range shifts toward higher values.

15. Ratio between QTc and AF Form The ratio between persistent and paroxysmal AF subsets was 1:2. The ranges of QTc duration in both subsets showed no significant differences.

16. Ratio between QTc and HR The ratio between patients with tachy-, normo-, and bradycardic AF was 13:6:1, respectively. In tachycardic AF, QTc duration is distributed over the whole range. With the decrease of HR the range is narrowed. In the bradycardic form, the distribution of QTc duration is shifted toward higher values.

17. Ratio between QTc and the Time of AF Evolution The ratio between the subsets with less than 10 years of evolution and more than 10 years was 4:1. In the subset of less than 10 years, the QTc duration range is wider; in the subset of more than 10 years, narrower.

18. Ratio between QTc and LVEF The ratio between patients with LVEF 20- 43%, 44-66%, and 67-88% was 1:4:2, respectively. With the decrease of LVEF, the QTc duration range is wider.

19. Ratio between QTc and FC of Chronic Stable Angina (CSA) The ratio between FC I, II, and III of CSA was 1:3:2, respectively. In the FC I and II subsets, the QTc range was between 351 and 470 ms. With the increase of FC, the QTc range shifts toward higher values.

20. Ratio between QTc and systolic BP The ratio between patients without HBP, with mild, moderate, and severe HBP (in regard to systolic BP) was 5:3:2:1. With the increase of systolic BP, the QTc range shifts toward higher values. In the subset of severe HBP, the range of QTc duration is narrower and is concentrated between 381 and 500 ms.

21. Ratio between QTc and Diastolic BP The ratio between patients without HBP, with mild, moderate, and severe HBP (in regard to diastolic BP) was 5:2:2:1. With the increase of diastolic BP, the range of QTc shifts toward higher values. In the subset of severe HBP, the range of QTc duration is narrower and is concentrated between 381 and 470 ms.

22. Ratio between QTc Duration and History of AMI The ratio between patients with history of AMI and without AMI, was 1:8. The QTc range in the subsets with history of AMI and without AMI, was similar.

23. Ratio between QTc and History of Stroke The ratio between the subsets with history of stroke and without stroke, was 1:8. In the subset with stroke, the range of QTc duration was lower.

24. Conclusions In the patients studied, the range of QTc duration was between 290 and 560 ms. The ratio between the patients with short, normal, and prolonged QTc was 1:16:7, respectively. The most frequent QTc duration was between 381 and 410 ms. The range of the QTc interval in men was greater than in women. The QTc range in subsets with persistent or paroxysmal and chronic AF was similar. With the decrease of HR, the QTc range decreased. In the subset with AF evolution of less than 10 years, the range of QTc was wider than in the subset of more than 10 years. As LVEF decreased, the QTc range became wider. With the increase of age, heart failure functional class, HBP degree, and HR decrease, the QTc range shifts to higher values. QTc range in the subsets with history of AMI or without AMI was similar. In the subset of patients with history of stroke, the range of QTc duration was lower than in the subset without history of stroke. For the diagnosis of AF, it is important to consider the QTc interval duration. The changes in QTc duration may be useful as a marker of therapeutic measures effectiveness.