Dynamic left ventricular obstruction: a potential cause of angina in end stage renal disease.
BACKGROUND
Patients with end stage renal disease (ESRD) often have angina which cannot be explained by coronary artery disease (CAD) alone. Symptoms are often attributed to systolic and diastolic dysfunction, arrhythmia or microvascular disease. This study proposes another potential cause for angina in renal failure, namely dynamic left ventricular obstruction (LVO).


METHODS
125 renal transplant candidates underwent dobutamine stress echocardiography and coronary angiography. LVO was defined as a peak LV outflow tract gradient >50 mm Hg.


RESULTS
None of the patients had LVO at rest. 15 (12%) developed obstruction with dobutamine. The mechanism was systolic anterior motion of the mitral valve in 13 and mid cavity obstruction in 2. Of 53 patients with angina, 26% had dynamic LVO compared to only 1% in those without angina (p=0.004). The proportion with severe CAD, parameters of systolic and diastolic function and haemoglobin levels were similar in patients with and without angina. Significantly more patients with obstruction had angina (93% vs 28%, p<0.001). LV end-systolic (p=0.03) and LV end-diastolic (LVEDD, p=0.03) diameter were reduced and LV fractional shortening (LVFS) increased (p= or <0.001) in those with LVO. Haemoglobin levels, septal wall thickness, estimated LV filling pressure, the proportion with a positive DSE and severe CAD were similar in the 2 groups. LVFS was independently associated with the development of significant obstruction (OR 1.12, 95% CI [1.002, 1.244] p=0.04).


CONCLUSIONS
Dynamic LVO occurs in 26% of ESRD patients with angina. In these patients, the angina could not be explained by severe CAD, impaired systolic or diastolic function. Such patients have smaller LV cavity size and increased LVFS.
Sharma
Rajan
R
Department of Cardiology, St George's Hospital, London, United Kingdom. rajdoc.sharma@tiscali.co.uk
Pellerin
Denis
D
Gaze
David C
DC
Mehta
Rajnikant L
RL
Gregson
Helen
H
Streather
Christopher P
CP
Collinson
Paul O
PO
Brecker
Stephen J D
SJ
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000209:etiology*; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003430:Cross-Sectional Studies; D018619:Echocardiography, Doppler, Pulsed; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014694:Ventricular Outflow Obstruction / Q000150:complications* / Q000503:physiopathology