Biomedical subjects

M St John Sutton

Publications and source records attributed to M St John Sutton.

39 records · Page 3Linked to original sources

PubMed1981

Echocardiographic assessment of left ventricular filling characteristics after mitral valve replacement with the St Jude medical prosthesis.

The major cause of late mortality and morbidity after prosthetic valve replacement is thromboembolism. The nidus for initiation of thrombus formation has been blood metal interfaces, and a new valve--the St Jude prosthesis--has therefore been developed without any metal components. We have assessed echocardiographically in 27 patients the effects of this valve on left ventricular filling characteristics when inserted in the mitral position and compared the findings with those in patients having mitral valve replacement with Starr-Edwards or Björk-Shiley prostheses and with those in patients undergoing repair of the native mitral valve. Echocardiograms were recorded and digitised. Measurements were made of the peak rate of increase of dimension (dD/dt) and duration of rapid filling. Values for the St Jude valve were 13.2 +/- 3.4 cm/s and 160 +/- 40 ms, respectively. The peak rate of dD/dt increase was significantly greater than with either the Björk-Shiley valve or the Starr-Edwards valve and was comparable with findings in mitral valve repair. The duration of the rapid filling phase was not significantly different from control values but was less than that of the Starr-Edwards valve. This study indicates that the new St Jude medical valve is less obstructive than either the Björk-Shiley or Starr-Edwards prostheses. This together with its low thrombogenicity suggests that further trials of this new valve should be undertaken.

Adolescent↗

PubMedDate not supplied

Congenital sinus of Valsalva aneurysm: a multiplane transesophageal echocardiographic experience.

Sinus of Valsalva aneurysm is a rare congenital anomaly which, if overlooked, may be associated with increased mortality and morbidity. Multiplane transesophageal echocardiography proved useful in identifying a variety of associated structural heart disease. This study sought to assess the accuracy of the surgical result on the basis of the multiplane transesophageal echocardiography findings and to describe patient demographics and clinical outcome in an Oriental patient cohort. From July 1984 to December 1995, clinical, catheterization, echocardiographic, and surgical results were retrospectively studied in 23 patients with documented sinus of Valsalva aneurysm. Compared with previous reports of Oriental patients, our patient cohort was older (p < 0.025), had more associated aortic, mitral, and tricuspid regurgitation (p < 0.01), but had fewer coexistent ventricular septal defects (p < 0.01), and had more associated coronary artery disease (9%). Multiplane transesophageal echocardiography precisely showed three undiagnosed and/or ambiguous transthoracic echocardiographic studies, and the preoperative transesophageal echocardiography TEE findings were confirmed intraoperatively in the last eight consecutive patients. We concluded that multiplane transesophageal echocardiography provides conclusive information and is the current technique of choice for diagnosis and clinical management of patients with sinus of Valsalva aneurysm; although the natural history of sinus of Valsalva aneurysm remains uncertain, it is likely that the incidence of unruptured sinus of Valsalva aneurysm is considerably higher in the elderly than has been previously reported.

Adolescent↗

PubMedDate not supplied

Modified rapid ventricular pacing: a chronic model of heart failure for evaluation of new surgical therapies.

Rapid ventricular pacing (RVP) in dogs creates a well characterized model of dilated cardiomyopathy. Standard pacing protocols use RVP at 240-260 beats/min for 2-4 weeks, and result in high mortality rates if continued longer. The authors describe a modification of RVP that results in significant heart failure by 4 weeks, but can be continued for up to 10 weeks with low mortality. Nineteen mongrels underwent RVP at 215 beats/min for 10 weeks. Serial pressure-volume analysis and echocardiography were performed in this model to assess longitudinally changes in left ventricular (LV) function and volumes. The mortality rate was 10%. Significant progressive LV dysfunction with concomitant LV enlargement was observed throughout the pacing period. Finally, norepinephrine levels were elevated at the end of pacing, consistent with an activated sympathetic system. This modified RVP protocol permits long-term pacing with a low mortality rate and results in progressive heart failure throughout the pacing period. This model would be useful in the long-term evaluation of newer surgical and medical therapies of the failing heart.

Animals↗