CC BY
9
Agnieszka Noszczyk-Nowak, Urszula Paslawska, Jozef Nicpon ®
Department of Internal Diseases and Parasitology with Horses, Dogs and Cats Clinic at the Faculty of Veterinary Medicine at the Wroclaw University of Environmental and Life Sciences, 50-366 Wroclaw, Poland.
HEART RATE TURBULENCE IN HEALTHY DOGS - PRELIMINARY STUDY
Key words: dog, EKG, heart rate turbulence
Introduction
Boxer the dogs of breed witch is predispose to occurrence of disturbance of rhythm of heart, in this ventricular tachycardia crossing in ventricular fibrilation, with have the cause of sudden heart death (SCD) with dog (5, 6, 7). The dogs' identification with enlarged risk of death with reason of heart disease has the important clinical meaning. However with dogs, having the disorder of rhythm of heart the menaced necessary SCD would sort the dogs' group they are the new diagnostic methods. It such parameters to this time in veterinary medicine to opinion of risk of sudden death were used was mainly how the ejection fraction (EF) and the fraction of shortening (SF) the left ventricle. Function of baroreceptors or valuation of late ventricular potentials did not pretend to introduce on wider scale of opinion of function, however large hopes be lace-up with measurements of heart rate turbulence (HRT).
Phenomenon HRT depends on short-lived change of frequency of heart rate after premature ventricular beats (VE or VPB) (fig. 1).
Fig.1 Premature ventricular beat (VE or VPB) with RR interval.
It acceleration after VE was observed was initial near (EA), and then late relaxation (LD) (3, 4, 8). The whole phenomenon lasts not longer than 15-20 next cycle of heart. It HRT was illustrated was behaviour sino-atrial node which after VE alters the frequency of discharges. A few parameters described of HRT, but the most
® Agnieszka Noszczyk-Nowak, Urszula Paslawska, Jozef Nicpon, 2008
312
often use to beginning turbulence (T0) and slope turbulence (TS). HRT is physiological phenomenon and to observe already mighty I for 1 VE. Is careful from at healthy persons TO should be < 0%, and TS > 2,5 [ms /# RR] (3). Norm are not well-known for dogs HRT. It the limitation in many works was showed was or the lack the HRT at ill with high risk of decease in later observation (1, 2, 4, 8, 9). It it in many works was showed was also, that the HRT is significant and independent parameter the prognostic relating the heart deceases value (1, 2, 4, 8, 9), and analysis of many investigations with the man's medicine caused that the opinion the HRT found in guidelines of European Heart Associacion the relating at ill the opinion of risk of decease with ischemic disease of heart and after infarct of heart muscle. It this time it however parameters were not studied in dogs HRT nor his usefulness was not confirmed to opinion of risk of sudden heart death.
Task, the aim of the article
The preliminary qualification of norms of parameters the TO and the TS the HRT for healthy dogs of the boxer breed ( to 1000 VE in 24 - the hour Holter monitoring
Material and method
The investigation was conducted on 10 health boxers.
The criteria of inclusion of to investigation:
1. age above 1 year
2. owner's agreement
3. correct results of blood test, the ions balances, as well as the function of kidneys and the liver
4. sinus rhythm in resting record of ECG Criteria of exclusion with investigation
1. age above 10 years
3. WBC <20 000 g / l, anemia, disorder in concentration ions - to time settlement, AST, ALT, urea, kreatynina - above norms
4. different rhythm than sinus rhythm in resting record of ECG
It the clinical investigation with all animals was conducted was as well as the morphological investigations (the number of erythrocyte, leucocytes, plates of blood) biochemical the blood (the urea, kreatyn, AST, ALT, K +, Na +, Mg2 +, Ca2 +, Cl -) in Laboratory the Departament of Internal Diseases and Parasitic from Clinic of the Horses' Diseases, the Dogs and the Cats of the Veterinary Medicine near use the apparatus and the materials of firm the Kodak. It apparatus was executed was investigation resting ECG Schiler AT then -1 or BTL. It the investigation after affirming of sinus rhythm was executed was the echocardiographic examination the aparaet will be executed Aloka 4000. After realization these the investigations the dogs with healthy dogs was conducted 24 - the hour the Holter monitoring - keeper the three - channel AsPEKT 702 the firm the Aspel or the ROZIN. After analysis of record of ECG of the Holter method, the analysis of parameters be has carried out the
313
HRT. It is careful, that to the opinion the HRT was credible which the presence be required in record of ECG the least 5 VE from answering tachograms together with (the record after stimulation min. 15-20 beats the electric evolutions of heart of sinus rhythm).
(RR1+RR2) - (RR-2 +RR-1)
TO =_ x100%
(RR-2+RR-1)
The TS was counted to made mean the time of duration of spaces the RR for 15 next stimulations of sinus rhythm after VE. Then for so the created draught the mean of spaces the RR crosses out for next 5 cycles the separate line of regress. Straight line about maximum inclination ( the most ornate) the the largest average relaxation of rhythm of heart describes on section 5 sinus stimulations after VE. Value of coefficient of such line answers the inclination the turbulence that is TS.
Results of resarch
It at 10 the dogs of breed the boxer, classified to investigation, the disorders were not affirmed was in morphological and the biochemical blood tests. Sinus, regular, rhythm, no premature ventricular stimulations in resting record of ECG in all dogs was affirmed. In echocardiographic examination the dimensions of atrials and ventricle of heart and the contractibility of left ventricle were correct. It in 24 the hour Holter monitoring - was affirmed was occurrence in number premature ventricular stimulations not crossing 100/24 h. We were calculated T0 and TS for choisen of VE, separately for registered in day stimulations and in night. The healthy dogs have premature ventricular beats mainly of per day, 3 dogs were not affirmed VE in the night. We were affirmed that T0 for registered in day VE has negative values (average =-15,28, SD = 11,26), which marks that the acceleration rhythm of heart after VE follows. Value T0 for registered in night stimulations had positive values (mean = 26,55, SD = 21,20), which marks the relaxation of rhythm after premature ventricular stimulation. At all studied dogs of value T0 were in draught of day < 0%, which is the value received for correct at healthy men. In draught of night T0 achieved the positive values, which is affirmed at healthy men also. TS with all dogs 2,5 ms /# RR (correct received at men value) and she carried out mean= 16,2; SD = 6,98.
314
900 800 700 600 500 400 300 200 100 0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Fig. 2. Example tachogram from appointed TS.
Conclusions
The results are the preliminary observations relating with the turbulence of rhythm of heart in dogs of the boxer breed and they will be continued, both with healthy dogs how and with heart diseases.
Reference
1. Francis J., Watanabe M., Schmidt G.: Heart rate turbulence: a new predictor for of risk of sudden cardiac death. A.N.E. 2005, 10, 102-109
2. Grimm W., Sharkova J., Christ M., Schneider R., Eng M, Schmidt G., Maisch B.: Heatr rate turbulence following ventricular premature beats in healthy controls. A.E. 2003, 8, 127-131
3. Guzik P., Schmidt G: Turbulencja rytmu serca - znaczenie kliniczne. Kardiologia Pol. 2006, 64, 198-207
4. Guzik P., Schmidt G.: Phenomenon of Heart-Rate Turbulence, Its evaluation and prognostic value. Card Electrophysol Rev 2002, 6, 256-261
5. Meurs K. M., Spier A.W., Miller M. W., Lehmkuhl L., Towbin J. A.: Familial Ventricular Arrhythmia in Boxers. J.Vet. Intern. Med. 1999, 13, 437439
6. Meurs KM., Spier A.W., Wright N.A., Atkins C.E.,. DeFrancesco T.C,.Gordon S.G, Hamlin R.L., Keene B.W., Miller M.W., Moise N.S.: Comparison of the effects of four antiarrhythmic treatments for familial ventricular arrhythmias in Boxer JAVMA 2002, 221, 522-52
7. Patterson, D.F,. Detweiler D.K. Hubben K, Bottes R.P.: Spontaneous abnormal cardiac rrhythmias and conduction disturbances in the dog - a
315
clinical and pathologic study of 3000 dogs. Am. J. Vet. Res. 1961, 22, 355369
8. Schmidt G, Malik M., barthel P: Heart-rate turbulence after vantricular premature beats as a predictor mortality after acute miocardial infraction. Lancet 1999, 353, 1390-1396
9. Watanable M.: Heart rate turbulence: 5-year review. Heart Rhythm 2004, 1, 732-738
Summary
Boxer the dogs of breed witch is predispose to occurrence of disturbance of rhythm of heart, in this ventricular tachycardia crossing in ventricular fbrilation, with have the cause of sudden heart death (SCD) with dog and the dogs' identification with enlarged risk of death with reason of heart disease has the important clinical meaning. We need new diagnostic methods to sort the dogs which are dangerous of SCD. This new methods it is heart rate turbulence. Phenomenon HRT depends on short-lived change offrequency of heart rate after premature ventricular beats (VE or VPB). The preliminary qualification of norms of parameters the TO and the TS the HRT for healthy dogs of the boxer breed ( to 1000 VE in 24 - the hour Holter monitoring. The investigation was conducted on 10 health boxers. The results are the preliminary observations relating with the turbulence of rhythm of heart in dogs of the boxer breed and they will be continued, both with healthy dogs how and with heart diseases.
Cmammx nadiumna do peda^ii 20.09.2008
316
