1,492 articles
RELAX trial
RELAX trial (NCT00763867): NHLBI-sponsored randomized trial of sildenafil versus placebo in 216 HFpEF patients; no improvement in peak VO2, walk distance, or clinical status, published JAMA 2013.
Renal arteriovenous malformation
Renal arteriovenous malformation (rAVM, kidney AVM) is a rare abnormal artery-vein communication in the kidney, congenital in about 25% of cases, presenting mainly with hematuria and treated chiefly by transcatheter embolization.
Renal parenchymal hypertension
Renal parenchymal hypertension is high blood pressure caused by disease of the kidney tissue itself, which retains sodium and water; it accounts for 3% to 5% of hypertension.
Renal sympathetic denervation
Renal sympathetic denervation (renal denervation, RDN) is a catheter-based procedure ablating renal sympathetic nerves with radiofrequency, ultrasound, or alcohol energy to lower uncontrolled blood pressure; FDA approved Recor Paradise and Medtronic Symplicity Spyral systems in November 2023.
Renovascular hypertension
Renovascular hypertension, also called renal hypertension, is secondary hypertension from renal artery stenosis (atherosclerosis ~90%, fibromuscular dysplasia ~10%) activating the renin-angiotensin system; medical therapy is first-line, with selective revascularization.
RENOVATE trial
RENOVATE-COMPLEX-PCI (NCT03381872) is a 1,639-patient Korean randomized trial showing IVUS/OCT-guided PCI reduced target vessel failure versus angiography guidance in complex coronary lesions, sustained at 5.3 years (10.5% vs 14.9%).
Reperfusion injury
Reperfusion injury, or ischemia-reperfusion injury (IRI), is paradoxical tissue damage caused by restoring blood flow after ischemia, affecting heart, brain, kidney, and gut; mechanisms include reactive oxygen species, calcium overload, and microvascular dysfunction.
RESCUE-AS trial
RESCUE-AS (NCT07335107), also called RESCUE-AS trial, is a phase 3 Chinese trial testing IV tirofiban after bridging therapy (EVT plus tenecteplase) in 564 patients with atherosclerotic large vessel occlusion stroke and successful reperfusion.
Resistant hypertension
Resistant hypertension is blood pressure that remains above goal despite three antihypertensive drugs of different classes including a diuretic, affecting roughly 5 to 10 percent of treated patients.
RESOLUTE-AC trial
RESOLUTE-AC (RESOLUTE All Comers, NCT00617084) was a randomized noninferiority trial of 2292 all-comer patients comparing the Resolute zotarolimus-eluting stent with the Xience-V everolimus-eluting stent; target lesion failure was 8.2% vs 8.3% at 12 months, with no differences through 5 years.
Retroperitoneal arteriovenous malformation
Retroperitoneal arteriovenous malformation (retroperitoneal AVM): a rare fast-flow vascular malformation with a dysplastic artery-vein nidus behind the abdominal cavity, causing heart failure, pulmonary hypertension, or bleeding; treated mainly by transcatheter embolization.
Revascularization strategy in chronic coronary disease
Revascularization strategy in chronic coronary disease is the choice among PCI, CABG, and medical therapy for stable disease, relieving angina and improving survival in selected anatomic subsets.
Rh deficiency syndrome
Rh deficiency syndrome, also called Rh-null syndrome or golden blood, is a rare autosomal recessive disorder (about 1 in 6 million) in which red blood cells lack all Rh antigens, causing mild chronic hemolytic anemia and severe transfusion incompatibility.
Rh disease
Rh disease, or Rh hemolytic disease of the fetus and newborn (erythroblastosis fetalis), occurs when an RhD-negative mother's anti-D IgG crosses the placenta and destroys RhD-positive fetal red cells; anti-D prophylaxis since 1968 has cut incidence about 95%.
Rheumatic aortic stenosis with insufficiency
Rheumatic aortic stenosis with insufficiency (ICD-11 BB72.0, ICD-10 I06.2) is combined narrowing and leaking of the aortic valve from chronic rheumatic heart disease, usually with fused commissures and concurrent mitral disease.
Rheumatic aortic valve insufficiency
Rheumatic aortic valve insufficiency (rheumatic aortic regurgitation): diastolic aortic valve leakage from rheumatic heart disease after group A streptococcal rheumatic fever; fibrotic restricted leaflets, prevented with penicillin prophylaxis, treated by surgery or TAVR.
Rheumatic aortic valve stenosis
Rheumatic aortic valve stenosis (ICD-11 BB70.0) is aortic valve narrowing from scarring after childhood rheumatic fever, common in Asia and usually with rheumatic mitral disease; treated by valve replacement.
Rheumatic aortitis
Rheumatic aortitis (ICD-11 1B41.10) is aortic wall inflammation from rheumatic disease, chiefly giant cell arteritis and Takayasu arteritis, also rheumatoid arthritis and ankylosing spondylitis, causing aneurysm, stenosis, and regurgitation.
Rheumatic mitral valve insufficiency
Rheumatic mitral valve insufficiency (rheumatic mitral regurgitation, ICD-11 BB61.0) is leakage of the mitral valve from rheumatic heart disease after Group A streptococcal infection; it predominates in the young and in low-income countries, and valve repair is the operation of choice.
Rheumatic mitral valve stenosis
Rheumatic mitral valve stenosis, also called rheumatic mitral obstruction, is narrowing of the mitral orifice from post-streptococcal valvulitis; valve area ≤1.5 cm² defines severity, treated by percutaneous balloon commissurotomy or surgery.
Rheumatic myocarditis
Rheumatic myocarditis (ICD-10 I09.0, ICD-11 BC42.3) is heart muscle inflammation from autoimmune reaction to group A streptococcal infection in acute rheumatic fever, marked by Aschoff bodies, with debated clinical significance versus valvular disease.
Rheumatic tricuspid valve stenosis
Rheumatic tricuspid valve stenosis (ICD-11 BB80.0) is rheumatic narrowing of the tricuspid valve, almost always with mitral disease (99.3%), causing venous congestion; diagnosed by echocardiography and treated mainly with valve surgery.
Rho(D) immune globulin
Rho(D) immune globulin (RhoGAM, anti-D, RhIG) is a plasma-derived IgG anti-D injection preventing Rh immunization in Rh-negative people; 300 µg doses at 26–28 weeks and within 72 hours postpartum cut HDFN by about 95%.
RIACE study
RIACE (Renal Insufficiency And Cardiovascular Events) Italian Multicenter Study: prospective cohort of 15,773 Italian type 2 diabetes patients (2006-2008, NCT00715481) showing non-albuminuric renal impairment predicts mortality and low retinopathy-CKD concordance.
Richter's transformation
Richter's transformation, or Richter syndrome, is the aggressive lymphoma (usually DLBCL) that develops in 2–10% of chronic lymphocytic leukemia/SLL patients, with poor survival and clonal relationship as key prognostic factor.
Right axis deviation
Right axis deviation (RAD): an ECG finding where the frontal-plane QRS axis exceeds +90°, caused by right ventricular hypertrophy, pulmonary embolism, COPD, or left posterior fascicular block, and associated with higher long-term mortality.
Right bundle branch block
Right bundle branch block (RBBB) is a disorder of the heart's electrical conduction in which the right ventricle is activated late, producing a widened QRS complex on the electrocardiogram.
Right outflow tract ventricular tachycardia
Right outflow tract ventricular tachycardia (RVOT-VT), also called idiopathic RVOT VT, is a benign triggered-activity VT from the right ventricular outflow tract in structurally normal hearts, showing LBBB inferior-axis ECG, treated with beta-blockers, calcium channel blockers, or curative catheter ablation.
Right ventricular failure
Right ventricular failure is the syndrome of systemic venous congestion, with or without low cardiac output, caused by right ventricular dysfunction, most often from left heart failure raising pulmonary pressures.
Right ventricular hypertrophy
Right ventricular hypertrophy (RVH), thickening of the right ventricle wall from chronic pressure overload, seen in pulmonary hypertension, cor pulmonale, pulmonary stenosis, tetralogy of Fallot; diagnosed by echo, ECG, cardiac MRI.