Abstract: SA-PO371
Liddle Syndrome and Recurrent Spontaneous Coronary Artery Dissection
Session Information
- Hypertension, CVD, and the Kidneys: Clinical Research
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Hypertension and CVD
- 1602 Hypertension and CVD: Clinical
Authors
- Seethapathy, Ritu, Landmark Medical Center, Woonsocket, Rhode Island, United States
- Klufas, Andrew, Roger Williams Medical Center, Providence, Rhode Island, United States
- Voiculescu, Adina Simona, Brigham and Women's Hospital, Boston, Massachusetts, United States
Introduction
Liddle Syndrome is an autosomal dominant form of resistant hypertension (HTN) characterized by suppression of plasma renin activity and aldosterone secretion with early onset HTN and hypokalemia.
Case Description
A 45-year-old woman with treatment resistant HTN since her twenties, presented to the ED for chest pain. She was hypertensive, with elevated troponins and ST-segment elevation on EKG. In the Cath Lab she was found to have mid-LAD occlusion secondary to dissection with subsequent balloon angioplasty, and was discharged on Carvedilol, Losartan, HCTZ, and DAPT. Two years later she developed similar chest pain with recatheterization showing spontaneous dissection of first obtuse marginal artery. She was placed on regimen of five maximally tolerated medications (Losartan/HCTZ, Carvedilol, Diltiazem, Clonidine, and Isosorbide Mononitrate).
Further workup showed low plasma renin activity and aldosterone, normal catecholamine levels, and chronic hypokalemia. Surveillance imaging showed a cavernous carotid artery aneurysm and renal artery beading suggestive of fibromuscular dysplasia (FMD), thought to demonstrate a shared pathophysiologic process. However, Renal Artery Doppler showed normal flow velocity bilaterally. Liddle Syndrome was suspected given unusual labs and lack of renal artery stenosis, and amiloride was recommended pending genetic test results.
Discussion
Liddle Syndrome is caused by mutations in genes encoding epithelial sodium channels (ENaC). Increased ENaC activity results in increased sodium reabsorption, causing HTN through intravascular volume expansion, and hypokalemia through high distal tubule potassium secretion. HTN also causes decreased renin and aldosterone production through JGA feedback.
Treatment involves potassium sparing diuretics (triamterene and amiloride), which block ENaC channels. Mutant ENaC channels prevent action of mineralocorticoid receptor antagonists (spironolactone). Genetic studies are required for confirmation as phenotypic variability often leads to misdiagnosis; however, it cannot definitively rule out disease as not all associated mutations are known.
Spontaneous coronary artery dissection (SCAD) has been associated with underlying connective tissue disease or arteriopathy, most commonly FMD. To our knowledge this is the first case reported of recurrent SCAD in the setting of possible Liddle Syndrome without evidence of FMD.