CARDIAC RHYTHM DISORDERS AND HYDROELECTROLYTIC ABNORMALITIES IN CHRONIC HEMODIALYSIS PATIENTS: IS THERE A CORRELATION?

1. Cardiology Department Uh Mohammed VI. 2. Nephrology Department Uh Mohammed VI. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 10 December 2019 Final Accepted: 12 January 2020 Published: February 2020

466 changes in volemia and electrolytes and occur frequently in hemodialyzed patients. Supraventricular arrhythmias and ventricular extrasystoles can occur in 20-88% and 76-100% of hemodialysis sessions respectively. The prevalence of atrial fibrillation in hemodialyzed patients ranges from 4.5% to 27%, depending on age, number of years spent on dialysis, and comorbidities. This is significantly higher than in the general population. Similarly, the average incidence of this arrhythmia is estimated at 2.7% per year in this population. At the ventricular stage, arrhythmias ≥ 3 according to the LOWN classification were reported in 13-37% of patients [2][3].The purpose of our work is to study and describe electrocardiographic disorders on the one hand, and metabolic abnormalities on the other, in chronic hemodialysis before during and after the hemodialysis session and to objective a possible relationship between arrhythmias and electrolyte abnormalities including dyskaliemia.

Materials and Methods:-
This is a descriptive prospective analytical study carried out in collaboration between the Department of Cardiology and Nephrology of the University Hospital of Marrakech, over a period of 6 months from May to October 2018.We included 56 chronic hemodialyzed patients either all patients of the hemodialysis center of the hospital IBN TOFAIL of Marrakech without particle selection with the exception of three patients followed for neuropsychiatric pathology. The hemodialysis age was greater than 12 months. Our patients are considered to be properly dialyzed by a ratio of Kt/V > 1.2 (K: the clearance of the filter urea which defines the performance of the dialysiist; t: time of the hemodialysis session in minutes; V: total volume of water contained in the patient's body expressed in litres). The dialysate used was bicarbonate, with a fixed concentration of sodium (138 mmol/l), calcium (1.5Meq/l), potassium (2-3 mmol/l), magnesium (0.5mmol/l).In our study, dyspnea was present in 53.6% of cases, including 26 cases with dyspnea class II (NYHA). Intermittent chest pain was experienced in 2 patients (3.5% of cases). Paroxystic palpitations were noted in 6 patients (10.7% of cases). There were no cases of syncope.Systolic blood pressure averaged 131.4 + /-22 mmhg. Diastolic blood pressure averaged 71 +/-13 mmhg. The heart rate averaged 78+/-10. Note that the LV ejection fraction was preserved in 96.4% of cases (54 patients).We have carried out in all our patients an 24 hours electrocardiogram (EKG) installed 2 hours before their hemodialysis session and this to cover the period per and post-dialysis on the one hand and a biological balance including kaliemia, natremia, calcemia, urea, creatinine and this before and after hemodialysis.The data collection is carried out using a preestablished sheet and the analysis of the results was carried out using the SPSS 20 software. The difference is considered significant if p<0.05.

Results:-
The average age of our patients was 49.89 years with extremes ranging from 16 to 86 years. A slight female predominance was noted (51.78% of cases) with an M/F sex ratio of 0.9. The majority of our patients had standard social insurance coverage. 10 patients (17.8% of cases) were diabetic; 24 were hypertensive (43% of cases); 16% of our patients had dyslipidemia; 10 patients were smoking (17.8% of cases). Heart disease was reported in 8 patients, 3 of whom had ischemic heart disease. Causal nephropathy is undetermined in 44.6% of cases (25 patients), diabetic in 17.8% of cases and hypertensive in 16% of cases (9 patients). Hemodialysis had an average age of 7.3 +/-6.8 years. 87% of our patients (49 patients) had two sessions per week or 9 hours on average. Vascular initiation was by arterial venous fistula (AVF) in 98.2% of cases (55 patients) and by tunneled catheter in 1 patient. Venous arterial fistula was radiocephalic in 50% of cases (28 patients) and brachiocephalic in 48.2% of cases (26 patients).

hours electrocardiogram:
The heart rate was regular in all our patients. Sinus tachycardia was objectified in 9% of cases during dialysis and 7% after the session.Left atrial hypertrophy was noted in 39.3% of cases. Right atrial hypertrophy was noted in 17.9% of cases. An incomplete left branch block was diagnosed in 3 patients. Left ventricular hypertrophy was noted in 25% of cases (14 patients). No cases of atrial fibrillation were diagnosed.A large QRS was found in 12.5% of the cases (7 patients). Isolated ventricular extrasystoles were objectified in 23.2% of the cases (13 patients) before, in 26.8% of the cases (15 patients) during and 48.2% of the cases (27 patients) after the hemodialysis session. Duplicate supraventricular extrasystoles were noted in only 1 patients before , in 3 patients during and in 6 patients after dialysis. Isolated supraventricular extrasystoles were highlighted in 42.9% (24 patients), 64.3% (36 patients) and 73.2% (41 patients) before , during and after their hemodialysis sessions respectively. Duplicate supraventricular extrasystoles were found in 16.1% of cases ( 9 patients) before hemodialysis, 23.2% of cases (13 patients) during and 25% of cases (14 patients) after the session. Other electrical changes are shown in Table I:

Discussion:-
The duration of the QRS was an average of 97ms in our series alongside Francisco COSTA study which was 98.2ms. A left ventricular hypertrophy (LVH) was found in 25% of the cases in our series against 71% of the cases in that of CISSE. The comparison of the other data with the electronic data in the literature is shown in Table IV: In our study, we found a decrease in Qtc duration, a decrease in T-wave amplitude with a statistically significant difference.We also objected to an increase in QRS duration after the hemodialysis session with a statistically significant difference compared to the Esqualli study (before dialysis: 80 ± 7.6 ms, after dialysis: 110 ± 8.0 ms, p 0.001). [11]on the other hand, we noted an increase in the prevalence of ventricular extrasystole in our series after the hemodialysis session but without it being statistically significant (p=0.1), this may be related to the absence of systolic LV dysfunction which increases the potential for ventricular hyperexcitability.Regarding biological data, it should be noted that the rapid elimination of potassium during haemodialysis, induced by a large transmembrane concentration gradient, is an over-added factor favouring the development of rhythm disorders during or immediately after the hemodialysis session [12]. A significant decrease in kaliemia has been noted in our study following the data in the literature, notably the study by Esqualli [11] which noted a significant and continuous decrease in kaliemia during thehemodialysis session (before dialysis: 6.4 ± 0.82, after dialysis: 4.21 ± 0.42 mmol/L, p 0.002)The other metabolic modifications found in our study are similar to those in the literature whose comparison is shown in Table V

Conclusion:-
Knowledge of the main factors that modulate the incidence of arrhythmias in dialysis patients provides a better understanding of rhythm disorders in this population. Changes in electrolyte concentrations, such as K+ and Ca2+ in per and post-dialysis, appear to be responsible for much of the rhythm disorders in hemodialysed patients. These ionic and metabolic variations during dialysis can lead to a considerable risk of heart disease, hence the value of close monitoring in person and post dialysis. Bibliography:-