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Published on: July 5, 2021
Prevalence, characteristics and natural course of inappropriate sinus tachycardia
Aino-Maija Still1, Pekka Raatikainen, Antti Ylitalo
1Department of Internal Medicine, Division of Cardiology, University of Oulu, P.O. Box 5000, FIN-900014, Finland.
Aims:
To study the prevalence, characteristics and natural course of inappropriate sinus tachycardia (IST).
Methods And Results:
The prevalence and characteristics of IST were evaluated in a random sample of 604 middle-aged subjects. Seven of the subjects (1.16%) fulfilled the contemporary diagnostic criteria of IST. The systolic (147+/-11 mmHg vs. 130+/-13 mmHg, P<0.001) and diastolic ambulatory blood pressures (92+/-7 mmHg vs. 81+/-8 mmHg, P<0.001) were higher among the subjects with IST than among the controls. The other laboratory, echocardiographic and personality measurements, with the exception of the hostility score (10+/-2 vs. 8+/-3, P<0.001), revealed no differences between the groups. The natural course and prognosis of the disorder was assessed among the subjects fulfilling the IST criteria and nine previously diagnosed IST patients. During a mean follow-up of 6.0+/-2.4 years, none of the subjects developed any clinical or echocardiographic evidence of structural heart disease despite ongoing palpitations, and there was no significant reduction in the 24-h average HR (9+/-2 bpm vs. 89+/-8 bpm, P=0.204).
Conclusion:
The prevalence of IST in a middle-aged population was higher than previously assumed. Despite the chronic nature of the disorder, the prognosis of IST was benign. The causal relationship between IST and hypertension and/or hostile personality type remains speculative.
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