ORALABST

RACTS

present, and 5¼ uniformly present and clear. For overall quality -¼unacceptable, 1¼ barelyacceptable, 2¼ acceptable, but below expectations 3¼ acceptable meets expectations, 4¼exceeds expectations, 5¼ outstanding.Results:

Conclusion: 1) The AC was easy to use and instructions were readily explained to indigentpts in a busy clinical setting. 2) Baseline sway and artifact were considered trivial. 3) P-wavesand overall quality were rated from acceptable to exceeding expectations, and tracings wereeasily interpreted by physicians with various levels of experience. 4) The AC provided quick,accurate assessment of cardiac rhythm in a remote area without land telecommunications.Disclosure of Interest: None Declared

O017

Beneficial Effects Of Renal Sympathetic Denervation On Pulmonary VascularRemodeling And Right Ventricular Function In Experimental Pulmonary ArteryHypertension

Qingyan Zhao*, xuejun jiang, zixuan dai, xiaozhan wang, zongwen guo, xule wang,congxin huangrenmin hoapital of wuhan university, wuhan, China

Introduction: The sympathetic nervous system and RAAS have been reported to be acti-vated and leading to deterioration in PAH.Objectives: We hypothesis that renal sympathetic denervation (RSD) decrease renin-angiotensin-aldosterone system (RAAS) activity and inhibit the progression in pulmonaryarterial hypertension (PAH).Methods: Nineteen beagles were randomized into control (n¼6), PAH (n¼7) andPAHþRSD (n¼6) groups. Animals underwent percutaneous pulmonary artery catheteri-zation to measure pulmonary hemodynamics before and 8 weeks after injection of 0.1 ml/kg dimethylformamide (Control dogs) or 2 mg/kg dehydromonocrotaline (PAH andPAHþRSD dogs). The dogs in the PAHþRSD group received renal artery ablation afterinjection. Eight weeks after injection, levels of Angiotensin II (Ang II) and pulmonary tissuemorphology were measured.Results: The levels of Ang II in plasma and AngII type 1 receptor expression (1.02�0.11 vs0.39�0.04, 0.38�0.05; P <0.01) in pulmonary arterial tissue were significantly increasedin PAH group compared with control and PAHþRSD groups. Dehydromonocrotalineincreased mean pulmonary arterial pressure (16 � 3.4 mmHg vs. 33 � 7.3 mmHg, P<0 .01), and this increase was prevented by RSD (14 � 3.6 mmHg vs. 17 � 3.9 mmHg,P¼0.19). Pulmonary smooth muscle cell proliferation were less in the PAHþRSD groupthan in the PAH group. Right ventricular end-diastolic diameter was significantly larger inthe PAH group compared with the PAHþRSD group.Conclusion: RSD suppressed the pulmonary vascular remodeling and decrease the pul-monary arterial pressure in experimental PAH.Disclosure of Interest: None Declared

O018

Intradialytic hypertension in end-stage renal disease patients treated by maintenancehemodialysis – a dynamic analysis

Adrian G. Tase*1, Claudiu Neacsu2, Valentina Georgescu3, Iuliana Ciocanea3, Anca Seica3,Paul Gusbeth-Tatomir31Cardiology, University of Pitesti, Emergency Hospital Pitesti, 2Nephrology, Emergency HospitalPitesti, 3Dialysis, Fresenius Nephrocare Center, Pitesti, Romania

Introduction: Intradialytic hypertension (IH) has been recently associated with increasedmorbidity and mortality in patients (pts) treated by conventional maintenance hemodialysis(HD). However, the characteristics of IH are currently less well described, although volumeoverload, hormonal and sympathetic activation, endothelial cell dysfunction, drug removal,and electrolyte imbalances have been proposed as culprits.Objectives: The goal of this study was to determine the dynamics of blood pressure (BP)related to biochemical values in this population.Methods: All clinically stable pts from our dialysis center, on HD for at least 3 months andwith valid body composition monitoring (BCM) were included. We recorded BP atentrance, hourly BP, and BP at the end of the HD session for 6 consecutive sessions. IH hasbeen defined as an systolic BP increase of �10 mmHg from pre- to post-HD. Pts- and

GHEART Vol 9/1S/2014 j March, 2014 j ORAL/2014 WCC Orals

dialysis-related parameters were recorded. We also noted actual dry body weight (DBW)and “ideal” body weight (G0) as derived from BCM.Results: We analyzed 139 pts (M/F ratio 84/55, mean age 56.6 �12.6 yrs, dialysis vintage60.2 �54.1 mo, 10.8% diabetics). Mean blood flow (BF) was 343 �55.7 mL/min, meandialysate flow (DF) was 603.6 �122.3 mL/min, dialysate sodium (dNa) was 135.9�1.2mmol/l, mean dialysate bicarbonate (dBic) 30.8�16.2 mmol/l. Within this group of pts,100 pts (71.9%) were using antihypertensive medication at home (1 drug 29%, 2 drugs37%, 3 - 21%, 4 or more 13%). Mean pre-dialysis systolic BP (sBP) was 143.6�19.7mmHg, and post-dialysis sBP was 142.5�19.2 mmHg. 22.5% pts had some degree of IH,whereas 2.3% had severe IH (arbitrarily defined as �20 mmHg increase of 6-sessions meansBP post versus pre-HD). Moreover, 36% pts experienced at least one session with apostHD peak of �20mmHg. 42.4% pts needed intradialytic antihypertensive medicationfor at least 2 sessions. The t-test did not find any differences between pts with and withoutIH in respect of BF, DF, ultrafiltration volume, dBic and pts characteristics. Pts with IH hada lower mean dNa by 0.6 mmol/l (t¼ -2.5, p<0.01). There were no differences between ptswith and, respectively, without IH regarding the pre- and post-HD hydration status asdetermined by BCM.Conclusion: IH is frequent and might be clinically important in many HD pts. Solely lowerdialysate sodium appears to be a significant contributor to IH in this study population. Thisfinding warrants for further prospective investigation.Disclosure of Interest: None Declared

O019

Evaluation of Lesion Characteristics and Thermodynamics for Symplicity andEnligHTN Renal Denervation Systems Using a Thermochromic Liquid Crystal Model

Sara Al Raisi*, Jim Pouliopoulos, Tony Barry, Aravinda Thiagalingam, Stuart Thomas,Gopal Sivagangabalan, Clara Chow, James Chong, Eddy Kizana, Pramesh KovoorCardiology, WESTMEAD HOSPITAL/ UNIVERSITY OF SYDNEY, Sydney, Australia

Introduction: Radiofrequency renal artery denervation is used to treat resistant hyper-tension. The two widely utilized systems are Symplicity and EnligHTN. However, lesion andthermodynamic characteristics for each platform have not been previously described.Objectives: We aimed to assess lesion dimensions and ablation characteristics for Sym-plicity and EnligHTN renal denervation systems using current recommended clinicalparameters.Methods: A total of 39 ablations were performed on a phantom renal artery model usingSymplicity (n¼17) and EnligHTN (n¼22). The phantom model was constructed with ablock of hollowed gel surrounding a vertical disc of thermochromic liquid crystal (TLC)film, with a temperature sensitivity between 50-78�C. Renal artery flow, at 500ml/min, wassimulated using saline with impedance equal to blood at 37�C. Radiofrequency ablationsfor duration of 120sec and 90sec for Symplicity and EnligHTN respectively were delivered,with optimal contact between electrode tip and gel interface. Lesion size was defined as aTLC zone with temperature rise of � 51�C.Results: Mean lesion depth was 3.815mm � 0.04 versus 3.440mm � 0.03 (p-value<0.001) for Symplicity and EnligHTN respectively. Mean width was 7.17mm � 0.08 versus6.23mm � 0.07 (p-value < 0.001), respectively. Mean ablation power was 6.23W � 0.7versus 5.18W � 0.5 (p-value ¼ 0.26) for Symplicity and EnligHTN respectively. WithEnligHTN, steady state temperature was achieved 20 seconds earlier, and was 150C higherthan Symplicity.

Conclusion: In thermochromic liquid crystal model, Symplicity formed larger lesionscompared to EnligHTN with lower catheter temperature. The difference in lesion size couldpartially be attributed to ablation duration. The clinical significance of our findings needs tobe further explored.Disclosure of Interest: None Declared

O020

Novel role for the large-conductance Ca2+-activated K+ channel (BKCa) as adeterminant of cardiac function

Vesna Nikolova-Krstevski*1, Arie Jacoby1, Inken Martin1, Gunjan Trivedi1, Halina Dobrzynski2,Diane Fatkin11Molecular Cardiology, Victor Chang Cardiac Research Institute, Sydney, Australia,2Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom

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