In the last few years, a significant increase in the number of patients with aortic stenosis requiring surgical or transcatheter aortic replacement (SAVR) or (TAVR) has been observed due to the larger aging population. Conduction disturbances requiring permanent pace maker implantation (PPMI) has been observed after SAVR and TAVR. In fact the incidence of PPMI following SAVR reached 11 to 13% while it occurred in7 to 36% of patients undergoing TAVR. The majority of rhythm problems are secondary to a significant trauma to the conduction system. In order to decrease the incidence of PPMI in patients undergoing SAVR, we developed a modified technique of SAVR that we applied on a group of 63 patients (group B) and we compared the incidence of PPMI in this group to the one observed in a second group of 62 patients who underwent the classic SAVR (group A). It was significantly lower in group B (3.2% vs 14.5%). In conclusion, The low incidence of PPMI (3.2%) observed in the modified SAVR group encourages us to recommend this technique in all patients undergoing biological SAVR especially that this technique is simple to apply highly reproducible and reliable. However, further multicenter and larger studies will help confirm our findings.

No abstract

Background and Aim of this Study: Patients presenting with aortic stenosis are offered surgical aortic valve (SAVR) or transcatheter aortic valve replacement (TAVR) as therapeutic options. However, both techniques are associated with postoperative conduction abnormalities necessitating PPMI. We evaluate in this paper the impact of a modified technique of SAVR- which aims to decrease the stress on the conduction system- on the incidence of PPMI for a 24 months period post-surgery. Methods: The perioperative course of 184 patients who underwent SAVR in Saint George Hospital University Medical center between January 2016 and June 2019 was assessed. The study compares the incidence of PPMI between two groups of patients. In group A, 92 patients underwent the classic SAVR and in-group B, and 92 patients underwent a modified SAVR. Results: The results revealed a significant decrease of PPMI from 12 to 2.2% during a two-year period follow up. A multi variate analysis showed that the modified technique was a strong predictor for PPMI post SAVR. In addition, this rate (2.2%) was lower than the ones reported after TAVR. Conclusion: This reproducible and reliable technique should be recommended whenever SAVR is performed. On the other hand, the low incidence observed may be adopted as a benchmark whenever TAVR is offered as a therapeutic option specially to intermediate and low risk patients. Moreover, this less traumatic technique should be retained whenever stent design modifications for TAVR are considered.

INTRODUCTION: The sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) are the cornerstones of cardiovascular adaptation.Autonomic dysfunction produces symptoms that overlap with hypofunction of the RAAS, namely hypoaldosteronism. The simultaneous presence of both disorders is not uncommon, especially in patients with CAD undergoing CABG surgery. Objective: This is the case of a patient with recurrent episodes of syncope and severe bradycardia, found to have both hyporeninemic hypoaldosteronism and carotid sinus hypersensitivity. We describe those interrelated phenomena and their association with CAD and CABG surgery. Case presentation: Our patient is a 63-year-old male with a history of hypertension (On Bisoprolol, Valsartan and Hydrochlorothiazide) and hyperlipidemia presenting for coronary artery bypass grafting for triple vessel disease. On the day of admission, the patient lost consciousness briefly and was transiently hypotensive (60/30 mm Hg) with a heart rate of 65 bpm. He reported having had similar self resolving episodes in the past at times of emotional stress. The next day, the patient underwent CABG surgery that was uneventful. Four hours later he developed another episode of unprovoked hypotension that resolved with the administration of neosynephrine. On postoperative day 3, while removing the central line from the right IJ vein, he lost consciousness and had a cardiac pause of 5 seconds. His blood pressure was 70/45 mm Hg. He regained consciousness immediately afterwards upon leg elevation. A carotid massage resulted in a 7 seconds cardiac pause, confirming the presence of carotid sinus hypersensitivity, necessitating the insertion of a pacemaker. However the patient lost consciousness again the next morning despite a normal functioning device. Endocrinology work up was initiated to rule out adrenal insufficiency. It revealed an undetectable aldosterone level with a low-normal renin level, ie hyporeninemic hypoaldosteronism.No hyponatremia, hyperkalemia, renal insufficiency or hypocortisolism were noted. Patient was started on fludrocortisone 0.1 mg daily, and his hemodynamics improved.He remained free of symptoms with normal electrolytes and vital signs on follow up since then. Conclusion: This case describes coexistence of hyporeninemic hypoaldosteronism and carotid sinus hypersensitivity. Although both entities might seem unrelated, a review of the literature and the physiology of cardiovascular hemodynamics revealed that CAD leads to autonomic dysfunction, which can present as carotid sinus hypersensitivity as in our case. In turn, the impaired adrenergic function blocks the activation of renin, leading to hypoaldosteronism and hypofunctioning RAAS. CABG surgery unmasked those interrelated entities. Patient was treated successfully with pacemaker placement and fludrocortisone replacement.

The sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) are the cornerstones of