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Biomedical subjects

P R Roy

Publications and source records attributed to P R Roy.

At least 19 recordsLinked to original sources

Percutaneous carotid artery stenting: a strategy in evolution.

BACKGROUND: Carotid stenting was initially proposed as an alternative to surgical endarterectomy for selected high-risk patients. More recently, patients of standard surgical risk are being considered for percutaneous treatment of their carotid disease. AIMS: To describe the clinical outcomes of an initial consecutive cohort of patients treated by carotid stenting at one institution. METHODS: Between December 1997 and July 2003, 111 patients underwent stenting of 118 carotid arteries. Peri-procedural and long-term outcome data were collected. RESULTS: Most patients (>70%) were high-risk candidates for endarterectomy. Stents were successfully placed in 117/118 carotid arteries (99.2%). Distal protection devices were used in 43/118 (36.4%). The peri-procedural rate of death or disabling stroke was 3/118 (2.5%). Death or any stroke occurred in 11/118 (9.3%). However, only 7/118 (5.9%) procedures resulted in death or any persistent stroke (neurological deficit >1 week post-procedure). No myocardial infarction occurred. Median length of post-procedure hospitalization was 1 day. Long-term follow up was possible for 101 patients (91.0%) over a mean period of 27.1 months. The Kaplan-Meier estimate of survival free of ipsilateral stroke 36 and 66 months after carotid stenting was 77.0 +/- 9.5% and 68.2 +/- 15.1%, respectively. The estimated survival free of any stroke or stent failure was 70.9 +/- 10.7% and 60.7 +/- 17.4%, respectively. The majority of late deaths (7/11) were due to cardiac disease. CONCLUSION: We conclude that stenting of carotid stenoses is feasible, with a high procedural success rate and low complication rate. Carotid stenting should be considered the procedure of choice for high-risk patients.

Adult↗

Intracoronary stenting without intravascular ultrasound guidance followed by antiplatelet therapy with aspirin alone in selected patients.

One hundred selected patients with 103 lesions were treated with the deployment of 117 Palmaz-Schatz stents without the use of intravascular ultrasound, followed by antiplatelet therapy with aspirin alone. Angiographic and clinical follow-up revealed 2 stent thromboses; 3 stents required redilation, and 3 patients required intervention for disease progression elsewhere, suggesting that this approach can be applied effectively in selected patients.

Aspirin↗

Contribution of left ventricular contraction to the generation of right ventricular systolic pressure in the human heart.

To determine whether left ventricular (LV) contraction contributes to the generation of right ventricular (RV) systolic pressure in humans, LV and RV pressures and their first derivative (dP/dt) were recorded simultaneously with micromanometer-tipped catheters in 11 conscious subjects. Seven subjects had normal LV and coronary angiograms. Four subjects had moderate LV dysfunction (resting ejection fraction 0.40 to 0.50), and three of these had coronary artery disease. During normal sinus rhythm, LV contraction slightly preceded RV contraction (mean 20 msec), and LV and RV dP/dt recordings showed single positive systolic peaks that were coincident. During endocardial pacing of the RV free wall, RV contraction preceded LV contraction (mean 23 msec) and two systolic RV dP/dt peaks were recorded, the first (peak I) occurring significantly before (mean +/- SD = 67 +/- 23 msec, p less than .01), and the second (peak II) coincident with the single systolic LV dP/dt peak. RV ectopic beats produced a similar RV dP/dt pattern, with peak I occurring 63 +/- 11 msec (p less than .01) before, and peak II coincident with the single LV dP/dt peak. Conversely, during LV ectopic beats, LV contraction preceded RV contraction (mean 63 msec) and two systolic RV dP/dt peaks were recorded, but peak I was coincident with the single LV dP/dt peak, while peak II occurred significantly later (63 +/- 26 msec, p less than .01). In two subjects right bundle branch block produced similar findings. In three subjects left bundle branch block produced little ventricular asynchrony (mean 14 msec), but did delay the development of peak LV dP/dt after LV contraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Patient selection for cardiac transplantation.

Since February 1984, 27 isotopic cardiac transplants have been performed in 25 patients. These 25 patients were from a pool of 45 patients who were accepted into the Programme. Sixteen patients have died awaiting a transplant, and four patients are presently on the waiting list. All patients accepted for cardiac transplantation were NYHA Class IV. There were 136 referrals during this period for cardiac transplantation, and 14 referrals for heart-lung transplantation. The commonest reason for non-acceptance into the Programme is that patients were considered not to be ill enough and to have a prognosis of more than six months. Patient selection is a key factor in ensuring a successful outcome with cardiac transplantation.

Adolescent↗

Emergency coronary artery recanalisation in acute myocardial infarction.

A 48-year-old man presented to hospital with prolonged ischaemic chest pain. No electrocardiographic or enzymic changes of acute myocardial infarction were found. Angiography performed five days later showed 75% luminal narrowing of the proximal left anterior descending (LAD) coronary artery, but no other significant abnormality. On the following day, he developed an acute anterior myocardial infarct. On repeat angiography, undertaken within 2 1/2 hours of the onset of symptoms, the LAD was found to be totally occluded. A guidewire was immediately passed through the occlusion, and streptokinase was infused through the left coronary artery for approximately 30 minutes. The vessel became patent immediately after the insertion of the guidewire, and remained so during the infusion of streptokinase. Coronary artery bypass graft surgery was successfully undertaken after the completion of the procedure.

Angiography↗

Hereditary prolongation of the Q-T interval. Genetic observations and management in three families with twelve affected members.

Three families with the prolongation Q-T interval are described. Two demonstrated the nonsex-linked dominant mode of inheritance of the condition without neural deafness (the Romano-Ward syndrome). Family A had four affected members in three generations. Family B had three affected members in two generations, but the parents of the affected children were distant relatives. Family C had five affected members in three generations. Of the nine living affected members, seven were asymptomatic and never experienced syncope. The remaining two, aged 7 and 9 years, respectively, had multiple syncopal attacks. Of three affected members who died, two had electrocardiograms before death. The thirds, an apparently healthy boy of 14 years, had a single syncopal attack 13 months before he died in his sleep. The nature of the dysrhythmia causing syncope was documented in two cases. One of the affected children was treated successfully with a permanent demand pacemaker and propranolol, the other with propranolol alone. The electrophysiologic findings and the management of both symptomatic and asymptomatic patients are discussed.

Adolescent↗

Fate of coronary collateral circulation after aorto-coronary saphenous vein bypass grafts.

The pre- and postoperative patterns of coronary artery collateral circulation have been studied in 34 patients who had saphenous vein bypass grafting. When the graft remained patent homocoronary collaterals could not be visualized after operation, but new intercoronary anastomoses frequently developed to other diseased arteries. When the graft and the bypassed artery were both obstructed there was a high incidence (5 out of 11) of myocardial infarction despite good preoperative collaterals.

Aorta, Thoracic↗

Haemodynamic events in right and left ventricle during angina induced by atrial pacing.

Atrial pacing to the point of angina or up to a maximum rate of 166/min was carried out in 37 patients during coronary angiography. In 9 patients with normal coronary arteries both the right and left ventricular end-diastolic pressures fell remained steady with increasing heart rate. The same response was observed in 14 patients with angiographically proven coronary artery disease. In the remaining 14 patients with provencoronary artery disease the end-diastolic pressure in the left ventricle rose at the point when the patient experienced angina. In 10 of this latter group there was a simultaneous rise in the right ventricular end-diastolic pressure. In 4 patients the rise in end-distolic pressure was seen in the left ventricle only. The haemodynamic events in the right ventricle during angina appeared in most cases to mimic the events occurring in the left ventricle. There was no correlation between the angiographic findings and the changes in end-diastolic pressure in the two ventricles during angina.

Angina Pectoris↗

Clinical experience with the Elema Vario pacemaker.

Early problems after implantation of an endocardial electrode for permanent pacing occur in many patients. Difficulties can be anticipated in many of these patients and their management made much easier by a knowledge of the daily endocardial threshold obtained in patients with an implanted Elema Verio pacing unit by a simple non-invasive technique using a magnet and electrocardiogram. Twenty patients are described in whom permanent pacing with an Elema Vario unit was undertaken. The practical advantages of this unit can be readily seen in the patient who developes exit block or in the patient with obstructive airways disease, in whom frequent coughing or right ventricular hypertrophy may make stable electrode placement difficult. The chief advantage of the Elema Vario pacemaker is the extreme simplicity with which knowledge of the endocardial threshold can be obtained.

Adams-Stokes Syndrome↗