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Biomedical subjects

D J Burstow

Publications and source records attributed to D J Burstow.

22 records · Page 2Linked to original sources

Fenestrated atrial septal aneurysm: diagnosis by transesophageal echocardiography.

The diagnosis of atrial septal defect by transthoracic echocardiography remains difficult in a small subset of patients because of either suboptimal acoustic windows or unusual anatomy, for example, fenestrated defects. We report the case of a 55-year-old woman with a fenestrated atrial septal aneurysm that was incompletely visualized by transthoracic echocardiography. Subsequent transesophageal echocardiography demonstrated three defects within the atrial septal aneurysm with left-to-right shunting across each defect. Normal pulmonary venous connections were also defined. All echocardiographic findings were confirmed at surgery. This case demonstrates the additional diagnostic accuracy of transesophageal echocardiography for detecting disease of the atrial septum.

Echocardiography↗

Angiotensin-converting enzyme and angiotensinogen genes in patterns of left ventricular hypertrophy and in diastolic dysfunction.

1. The association of different patterns of left ventricular hypertrophy and diastolic dysfunction with angiotensin converting enzyme (ACE) genotypes or angiotensinogen dinucleotide repeat alleles were studied in human subjects. 2. Three abnormal patterns of hypertrophy (remodelled, eccentric and concentric) were associated with a history of hypertension. The presence of remodelled or concentric hypertrophy was associated with diastolic dysfunction. 3. There was no difference between the frequencies of the ACE genotypes in normotensive and hypertensive subjects, in subjects with normal ventricles and those with different patterns of left ventricular hypertrophy, nor in subjects with normal and abnormal diastolic function. Similarly, there was no difference between the relative frequencies of AGT alleles in the same clinical subgroups. 4. We conclude that in this population of hospital patients, variants of the ACE and AGT genes do not contribute to the presence of different patterns of hypertrophy or to diastolic dysfunction.

Adult↗

Genetic variants of proteins from the renin angiotensin system are associated with pressure load cardiac hypertrophy.

1. The relationship between the angiotensinogen (AGT) T174M, angiotensin converting enzyme (ACE) insertion/deletion (I/D) and the angiotensin II type 1 receptor (AT1) genetic markers and left ventricular hypertrophy was examined in normal subjects and those with aortic stenosis. 2. Subjects with aortic stenosis had higher left ventricular systolic pressure and relative wall thickness (RWT) compared with normal. However, within aortic stenosis subjects, left ventricular RWT did not correlate with left ventricular systolic pressure or with aortic valve area. 3. In subjects with aortic stenosis, left ventricular RWT was higher in those with ACE DD (P < 0.05) or AGT T174M (P < 0.06) compared with those with the ACE II or ID genotype or AGT TT174 genotype. No relationship was observed with any of the AT1 alleles. The ACE and AGT genetic markers independently predicted left ventricular RWT in aortic stenosis. No association was observed between these genotypes and left ventricular RWT in normal subjects. 4. The data suggest that the AGT T174M and ACE I/D genotypes may act together to influence the degree of hypertrophy in subjects with aortic stenosis. 5. In patients with aortic stenosis, genetic variants of proteins from the renin angiotensin system may be at least as important as left ventricular systolic pressure in determining the degree of left ventricular hypertrophy and could therefore explain the clinical variation observed in the progression to cardiac dysfunction.

Adult↗

The Cryolife-O'Brien stentless aortic porcine xenograft valve.

BACKGROUND: The advantageous design of the Cryolife-O'Brien stentless porcine aortic valve permits specific quick, easy, supravalvular implantation using single layer continuous 3-0 polypropylene suture. The advantages, contraindications, and implantation errors to avoid are detailed. The use of this valve for aortic valve replacement in the elderly population has been directed to proving its efficacy and establishing its grounds for durability while maintaining all of the advantages of a stentless tissue valve. METHODS: From December 1992 to September 1998, this valve was used in 240 patients (mean age 73 years: 15% > 80 years), 45% receiving associated coronary artery grafting (2.4 grafts per patient). Left ventricular (LV) myomectomy was necessary in 12% of patients. Detailed postoperative follow-up (100%) analysis included 650 serial echocardiographic studies. RESULTS: The 30-day mortality was low at 1.2% (3 deaths of 240 elderly patients). Ten patients had late mortality (1.5 months to 5 years), all nonvalve related. No structural failure and one only explant for endocarditis have occurred. Echocardiographic analyses have shown low mean transvalvular gradients in relationship to time (8.18 mmHg at 18 months) and to valve size (8.52 mmHg for a 23-mm host aortic annulus). Incompetence has been zero or a trace in 97% of the patients at 21/2 years. No patient over the 6 years shows valve deterioration. CONCLUSION: Six years of experience with this stentless valve in 240 elderly patients has revealed the many advantages of this safe, composite, and truly stentless device that is assembled without the need for Dacron support. Excellent sustained hemodynamics with low gradients, minimal regurgitation, and a good effective orifice have been coupled with low immediate mortality, no intrinsic valve failure, and one explant for endocarditis. Marked LV regression and minimal late valve-related complications confirm the safety and advantages of this stentless valve.

Aged↗