Evaluation of atrial electromechanical functions in dipper and nondipper hypertension patients with atrial strain, P WAW dispersion and P terminal force

Background: Hypertension (HT) is a risk factor in the development of end-organ damage such as cardiovascular, cerebrovascular and renal disease. It is known treatment of hypertension is associated with the reduction in the risk of occurrence of these diseases. ABPM is preferable to office blood pressure measurement for diagnosis and treatment of HT. Patients with NDHT pattern in ABPM have higher rate of cerebrovascular disease, left ventricular mass, cardiovascular morbidity and mortality. Strain (S) and Strain Rate (SR) are useful in quantitative determination of regional myocardial function at subclinical stage before observed affecting the conventional ECHO parameters. Diagnosis and management of heart disease in these techniques are now finding wider areas. P terminal force has been shown to be associated with AF, stroke, LVH and the composite end point of death or hospitalization due to the heart failure. The aim of this study is to investigate the effect of DHT and NDHT pattern on the LA myocardial diastolic function in hypertensive patients by two-dimensional speckle tracking echocardiography and ECG parameters. Materials and Methods: Between August 2015 and May 2016, 72 hypertensive patients and 39 no non-disease control group admitted to Akdeniz University Medicine Faculty Department of Cardiology were included in this study. Patients with HT have been established with do not have target organ damage detected by physical examination, laboratory and conventional imaging methods. Patients were grouped by the blood pressure monitoring as dipping (DHT) and nondipping (DHT). Patients who are not at least 10% reduction in blood pressure overnight, was classified as NDHT. We investigate conventional echocardiographic parameters by using 2D echocardiography, mitral input current with pulsed wave Doppler, left ventricular filling pressures by Tissue Doppler, global function of the left atrium by strain imaging in these patients and control group. P wave dispersion and P terminal force value were calculated by applying electrocardiogram in all participants. Results: Totally, 111 participants aged with 19 to 80 enrolled in the study. In DHT group had 30 participants (13 female (43.3%), 17 male (56.7%)), in NDHT group had 42 participants (21 male (50%) and 21 female (50%)). In control group had 14 female (%35,9), 25 male (%64,1) participants. Both patient groups compared with control group there were no differences with height, gender and smoking prevalence. There was no difference between the age in groups of DHT and NDHT (55,33±10,58 vs.57,38±10,9) and the control group consisted of younger patients (34,44±10,4). In the control group, weight, BMI, BSA values were lower compared to DHT and DHT groups, but there was no difference between DHT and NDHT groups. Heart rate was similar in all three groups but SBP and DBP measurements were significantly greater in DHT and NDHT groups (control group: 117,3±7,6 / 70,5±6,7 mmHg, DHT group: 138,0±19,9 / 84,3±12,3 mmHg, NDHT group: 137,9±15,9 / 84,0±11,6 mmHg). DHT and NDHT groups were similar in duration to have HT disease. The SBP and DBP values were significantly lower in the control group than the patient groups during examinations (control group: 117,3±7,6 / 70,5±6,7 mmHg, DHT group: 138,0±19,9 / 84,3±12,3 mmHg, NDHT group: 137,9±15,9 / 84,0±11,6 mmHg). In the control group, Ao, LA, IVS, PwD and left ventricular mass index (LVMI) were lower than patient groups (p<0,05). There was no significant difference in early diastolic mitral flow velocity between three groups (mitral E) and late diastolic mitral flow velocity (mitral A) was significantly lower in control group (p<0,05). Mitral E/A ratio was higher in the control group. Mitral A and Mitral E/A ratio were similar in DHT and NDHT groups. Mitral lateral e (LATEm), mitral lateral s (LATS), mitral septal e (SEPEm) values were significantly higher in control group than both patient groups (p<0,05). Mitral lateral a (LATAm), mitral septal a (SEPAm), mitral septal s (SEPS) values were similar in all of three groups. Mitral deceleration time (DT), isovolumetric relaxation time (IVRT) and myocardial performance index (MPI), Mitral E/Em ratio were lower in control group (p<0,05) but there was no difference between DHT and NDHT groups. Electromechanical delay times were significantly higher in NDHT patients according to DHT patients and control group (NDHT group: inter-atrial PA:32,8±8,4 msn, intra left atrial PA:19,3±7,1 msn, intra right atrial PA: 13,5±5,9 msn; DHT group: inter-atrial PA:25,2±7,1 msn, left atrial PA:14,9±6,3 msn, right atrial PA:10,3±4,4 msn, p<0,05). Similarly, in DHT group electromechanical delay times were significantly higher than control group (control-group: inter-atrial PA:15,9±6,9msn, left atrial PA:9,2±5,6 msn ve right atrial PA: 6,7±2,3 msn, p<0,05). In control group LA presystolic volume index was lower than patient groups, on the other hand there was no difference between DHT and NDHT groups (respectively: LAVIpreP:11,08±2,93 cm3/ml, 15,51±5,83 cm3/ml, 16,38±6,51 cm3/ml). In terms of LAVI, there was no difference between DHT and NDHT groups. In both patient groups strain rates were lower than control group and in NDHT patients, all three strain parameters were significantly lower than DHT and control groups (p<0,05). There was no significant differences about Pmin value between all groups, in contrast patient groups have higher Pmax, PWD and PTF values than control group. Also in NDHT group same values were higher than DHT group (p<0,05). Conclusion: Hypertensive patients with NDHT pattern lead further deterioration in atrial electromechanical deformation parameters compared with DHT patients. As a result, NDHT pattern also causes adverse atrial remodeling. We believe that further studies are warranted to demonstrate the long-term prognostic significance of these findings. Key words: Hypertension, dipper, non-dipper, two-dimensional longitudinal strain, P wave dispersion, P terminal force