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P A Dodds

Publications and source records attributed to P A Dodds.

5 recordsLinked to original sources

Vasoconstrictor peptides and cold intolerance in patients with stable angina pectoris.

BACKGROUND: The exact mechanism that explains the phenomenon of cold intolerance in patients with angina remains controversial. Although the response to the effects of a cold environment has been examined in these patients, their response to cold air inhalation has produced conflicting results. In addition, the possible role of vasoactive peptides in the pathophysiology has not been explored. OBJECTIVES: The aims of this study were to examine the response of patients with stable angina to the effects of cold air inhalation during exercise testing, and to investigate the possible role played by the vasoconstrictor peptides endothelin-1 (ET-1) and angiotensin-II (AT-II) in the pathophysiology. METHODS: In a randomised order, 12 men with stable angina, whose medication had been stopped, underwent two separate symptom limited treadmill exercise tests. At one visit the patients exercised while breathing room air and at the other visit they exercised while breathing cold air from a specially adapted freezer. Serial peripheral venous blood samples were taken for ET-1 and AT-II estimations during each visit. RESULTS: Cold air inhalation resulted in a significant reduction in the mean time to angina (232.7 (20.4) s v 274.1 (26.9) s, P = 0.04) and the mean total exercise time (299.5 (27.0) s v 350.3 (23.9) s, P = 0.008), but no significant change in the time to 1 mm ST depression (223.3 (29.0) s v 241.3 (29.2) s, P = 0.25). There was no significant difference between the rate-pressure products at the onset of angina (P = 0.13) and the time to 1 mm ST depression (P = 0.85), but at peak exercise the rate-pressure product was significantly lower in patients breathing cold air as opposed to room air (P = 0.049). There was an equivalent significant decrease in ET-1 concentrations at peak exercise compared with that at rest at both visits (room air 5.0 (0.7) pmol/l v 4.3 (0.7) pmol/l, P = 0.03; cold air 4.4 (0.6) pmol/l v 3.8 (0.5) pmol/l, P = 0.02). There was a significant increase in AT-II concentrations 10 min after peak exercise in patients breathing room air (39.2 (6.1) pmol/l v 32.1 (4.8) pmol/l, P = 0.01) which was not repeated during cold air inhalation (36.6 (3.4) pmol/l v 28.3 (3.4) pmol/l, P = 0.07). CONCLUSIONS: Cold air inhalation in patients with stable angina results in an earlier onset of angina and a reduction in exercise capacity. Both peripheral and central reflex mechanisms appear to contribute to the phenomenon of cold intolerance. Peripheral ET-1 and AT-II do not appear to play a significant role in the pathophysiology.

Aged↗

Transmitral Doppler assessment of left ventricular diastolic function during coronary artery bypass surgery.

OBJECTIVE: To evaluate which Doppler transmitral velocity indices of left ventricular diastolic function change with alteration of left ventricular filling pressure. METHODS: Twenty-two patients undergoing coronary artery bypass surgery. The effect of fluid loading on indices derived from the transmitral Doppler waveform, recorded by a trans-oesophageal echocardiography, was evaluated using a generalised linear statistical model. RESULTS: E-wave maximum velocity, E-wave acceleration time and slope, E-wave deceleration slope, A-wave maximum velocity and E/A wave maximum velocity ratio showed significant changes after alterations in left ventricular filling pressure. E-wave deceleration time and E-wave maximum velocity/time velocity integral showed no significant change after fluid loading. CONCLUSION: Several commonly used Doppler derived indices of left ventricular diastolic function are significantly affected by changes in filling pressure of the left ventricle. This may limit the usefulness of the Doppler method for serial assessment of diastolic function when the left ventricular filling pressure has changed between assessments. Only the E-wave deceleration time did not show significant changes and might be a useful Doppler index for the serial measurement of left ventricular compliance but this needs to be confirmed with haemodynamic measurements.

Adult↗

Delayed complications after myocardial contusion.

A 45 year old farmer was kicked in the chest by a horse. In the days following the injury episodic breathlessness developed and he was admitted to hospital with right ventricular failure and pulmonary emboli. Echocardiography showed global right ventricular dysfunction but a right ventricular mural thrombus, the likely source of the pulmonary emboli, was not seen. He gradually recovered after treatment with anticoagulant. One month later he presented with a further complication--complete atrioventricular dissociation--that required a dual chamber pacemaker implantation. This patient had few initial manifestations of right ventricular myocardial contusion and this case illustrates that such patients should be closely monitored for delayed complications.

Contusions↗

Screening the aged in general practice.

We describe a comprehensive screening project in a general practice in which patients over the age of 65 were assessed both socially and medically. We conclude from our results that there was little treatable but previously undiagnosed illness within the community studied.

Aged↗