Biomedical subjects

Andrew J Kerr

Publications and source records attributed to Andrew J Kerr.

4 recordsLinked to original sources

PubMed2006

Longitudinal left ventricular contractile dysfunction after exercise in aortic stenosis.

OBJECTIVE: To determine whether longitudinal left ventricular systolic function measured by Doppler tissue imaging (DTI) after exercise can identify early left ventricular dysfunction in asymptomatic patients with moderate-severe aortic stenosis. DESIGN: Case-control study. SETTING: Outpatient cardiology departments. PATIENTS: 20 patients with aortic stenosis, with or without equivocal symptoms, a peak aortic valve velocity > or =3 m/s, and left ventricular ejection fraction >50% and 15 aged-matched normal controls. INTERVENTIONS: Echocardiogram performed at rest and immediately after treadmill exercise. MAIN OUTCOME MEASURES: The peak systolic velocity of the lateral mitral annulus (S') by DTI at rest and immediately after exercise, exercise capacity, exercise systolic blood pressure and the plasma level of B-type natriuretic peptide (BNP). RESULTS: For patients with aortic stenosis, mean (SD) aortic valve area was 0.95 (0.3) cm(2). At rest, S' was similar for patients with aortic stenosis and controls, respectively (8.5 (1.5) vs 9.1 (1.8) cm/s, p = 0.15). However, after exercise, S' (12.2 (3.2) vs 17 (2.8) cm/s, p<0.001) and the increase in S' between rest and exercise (4 (3) vs 7.9 (1.5) cm/s, p<0.001) were lower in patients with aortic stenosis. In patients with aortic stenosis, a smaller increase in S' after exercise was associated with lower exercise capacity (r = 0.5, p = 0.02), a smaller increase in exercise systolic blood pressure (r = 0.6, p = 0.005) and higher plasma level of BNP (r = 0.66, p = 0.002). CONCLUSION: In asymptomatic patients with moderate-severe aortic stenosis a lower than normal increase in peak systolic mitral annular velocity after treadmill exercise is a marker of early left ventricular systolic dysfunction.

Aged↗

PubMed2003

Associations between plasma natriuretic peptide levels, symptoms, and left ventricular function in patients with chronic aortic regurgitation.

In 40 patients with chronic moderate to severe aortic regurgitation, brain natriuretic peptide, N-brain natriuretic peptide, and atrial natriuretic peptide were higher in symptomatic patients compared with asymptomatic patients after adjustment for age, gender, and ejection fraction, but each natriuretic peptide correlated weakly with echocardiographic measures of left ventricular size and function. In patients with chronic aortic regurgitation, measurement of natriuretic peptide levels may provide information on left ventricular function in addition to echocardiography.

Adult↗

PubMed2003

Plasma natriuretic peptide levels increase with symptoms and severity of mitral regurgitation.

OBJECTIVES: This paper will describe associations between plasma natriuretic peptide levels and the severity and symptoms of mitral regurgitation (MR). BACKGROUND: A biochemical test that assisted grading of the severity of MR and the interpretation of symptoms would be of clinical value. METHODS: Forty-nine patients with isolated MR and left ventricular (LV) ejection fractions (EFs) of >55% underwent transthoracic echocardiography, assessment of symptoms, and measurement of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and its amino-terminal portion, N-BNP. RESULTS: The level of each natriuretic peptide rose with increasing severity of MR and with increases in left atrial (LA) dimensions (p < 0.001 for all comparisons), but no significant correlation existed between any natriuretic peptide and the LV dimensions or EF. Natriuretic peptide levels were higher in symptomatic MR (n = 16, BNP geometric mean 16.9 [95% confidence interval (CI) 13.3 to 21.4] pmol/l) compared with asymptomatic MR (n = 33, BNP 7.1 [95% CI 6.0 to 8.4] pmol/l, p < 0.001), and higher in asymptomatic MR than in normal controls (n = 100, BNP 5.3 [95% CI 4.8 to 5.8] pmol/l, p < 0.0001). These differences were similar for N-BNP and ANP and remained statistically significant (p < 0.05) after adjustment for echocardiographic measures of LV function and severity of MR. Both the sensitivity and the specificity for symptoms for the natriuretic peptides (area under receiver-operator characteristic curve for BNP = 0.90, N-BNP = 0.89, ANP = 0.89) were similar to the MR score (0.88) and greater than for LA dimension (0.81), vena contracta width (0.82), and LV end-systolic dimension (0.63). CONCLUSIONS: Plasma natriuretic peptides levels increase with the severity of MR and are higher in symptomatic compared to asymptomatic patients, even when LV EF is normal.

Adult↗

PubMed2003

Interatrial septal mobility predicts larger shunts across patent foramen ovales: an analysis with transmitral Doppler scanning.

BACKGROUND: The association of patent foramen ovale (PFO) with cryptogenic stroke is strongest in patients with larger shunts and patients with atrial septal aneurysms (ASAs). We postulated that the potency of ASA as a risk factor for stroke relates to the size of shunt across PFOs associated with mobile atrial septae. The purpose of this study was to investigate the relationship between atrial septal mobility and the degree of right-to-left shunting with a transthoracic transmitral Doppler scanning (TMD) contrast technique. METHODS: In 165 consecutive patients, transthoracic TMD recordings were made during a saline contrast study with the patient at rest and after a maneuver to increase right atrial pressure. Bubble transit corresponded to high intensity signals in the velocity envelope of the mitral inflow profile and was quantified by a bubble score. RESULTS: A PFO was diagnosed in 59 patients (36%). In 50 patients with PFO and adequate echocardiography images, the incidence of ASA was 52%. In this group, both total septal mobility and leftward deviation predicted the TMD bubble score at rest (Spearman rho 0.64, 0.64, respectively, P <.001) and after the maneuver (Spearman rho 0.74, 0.73, P <.001). In 28 patients with cerebral ischemic events, the maneuver bubble score was predictive for cryptogenic stroke (P =.02, odds ratio 7.58). There was a trend toward significance between total septal motion and cryptogenic stroke (P =.06). CONCLUSION: Atrial septal mobility predicts the degree of right-to-left shunts across PFOs. The role of excessive septal mobility in the etiology of stroke may therefore be caused by the greater opportunity for paradoxical embolism because of the size of the associated trans-PFO shunt.

Adult↗