Acquired internal mammary artery to pulmonary artery fistula following bypass surgery.

We report two patients with acquired fistulas between the internal mammary and pulmonary arteries after coronary bypass surgery. This is a rare complication of bypass surgery and may be a cause of recurrent angina postoperatively due to coronary artery steal. A table of all the cases reported in the literature is compiled.

An evaluation of self-recorded blood pressure during drug trials.

To our knowledge, there have been no published comparisons of different techniques for measuring blood pressure during clinical trials. We undertook a comparison during clinical trials with verapamil and prazosin. During an open trial of verapamil we compared the treatment-induced blood pressure reductions as measured by clinic, intra-arterial, and self-recorded methods. The mean reduction in blood pressure was 38 +/- 13.6/20 +/- 10.1 mm Hg for clinic blood pressure, 24 +/- 17.9/16 +/- 7.3 mm Hg for self-recorded blood pressure, and 23 +/- 12.3/19 +/- 10.1 mm Hg for mean daytime intra-arterial blood pressure. During prazosin treatment the mean reduction in blood pressure was 28 +/- 21.5/18 +/- 8.5 mm Hg for clinic blood pressure, 21 +/- 20.5/6 +/- 13.7 mm Hg for self-recorded blood pressure, and 18 +/- 19.2/5 +/- 9.6 mm Hg for mean daytime intra-arterial blood pressure. There was little agreement between methods within individual patients and for group comparisons of intra-arterial or clinic methods. There was, however, good agreement between intra-arterial and self-recorded methods. This study suggests that self-recorded blood pressure recording is suitable for monitoring efficacy of antihypertensive agents in a group of patients, although caution must be exercised when interpreting the effects of therapy when measured by indirect methods in an individual patient.

Is the blood pressure the same in both arms?

It is generally believed that there are blood pressure differences between the right and left arms, but most of the validation studies have used nonsimultaneous measurements. It is important to know whether there is a difference, as methodological comparisons are often made using a different technique on each arm. We have measured the blood pressure simultaneously in both arms in 91 patients, using two observers and two cuffs to provide eight measurements in a fully balanced design. The mean difference in blood pressure between the arms (left/right) was -1.3 (SE 0.4)/1.1 (SE 0.3) mmHg. Mean differences of the same magnitude were found between the two observers, and between the cuffs. Thus, no systematic difference of any consequence was found, although individual patients had mean between-arm differences in blood pressure of up to 10 mmHg. These results suggest that no significant bias is introduced in methodological comparisons that use both arms.

Acquired aorto-pulmonary fistula--case report.

Two reports of the rare condition, acquired aorto-pulmonary fistula, are presented, one the result of acute aortic dissection, the other, giant cell aortitis. The presentation, diagnosis, and management are discussed and the literature reviewed.

Evaluation of the Remler M2000 blood pressure recorder. Comparison with intraarterial blood pressure recordings both at hospital and at home.

The Remler M2000 is a semiautomated device that has been used to collect epidemiological data and assess blood pressure variability. It has been subjected to limited evaluation in operation, however, and no studies of its accuracy away from the hospital or office environment have been undertaken. We recruited a group of 28 patients with essential hypertension who were undergoing intraarterial ambulatory blood pressure monitoring and compared the intraarterial recordings with those made with the Remler instrument both at home and in the hospital. The Remler recordings were also compared with simultaneous indirect blood pressure measurements made with the random zero sphygmomanometer. The mean difference between the Remler and intraarterial blood pressure recordings was -3/7 in the hospital and 7/0 at home. All standard deviations were greater than 10 mm Hg, indicating large between-subject variability. Overall, the relationship of the Remler M2000 readings to intraarterial pressures was as close if not closer than standard indirect sphygmomanometry and thus might provide useful data for epidemiological surveys or drug trials. It would appear that for accurate measurement of short-term blood pressure variation and 24-hour recording, intraarterial recording is the method of choice.

The role of a slow channel inhibitor, verapamil, in the management of hypertension.

The 'Oxford' system for continuous monitoring of the ambulatory blood pressure was used to assess the changes in blood pressure following therapy with the slow channel inhibitor, verapamil. Sixteen patients were studied on no therapy and following a minimum of 6 weeks therapy (dose range 120-160 mg t.d.s.). During each study patients underwent standardized physiological tests including tilt, isometric handgrip and dynamic bicycle exercise. Verapamil was demonstrated to produce a consistent reduction of blood pressure over most of the 24 h period studied but this was most marked during the day. Heart rate was also reduced. There was no postural hypotension and the absolute responses to dynamic and isometric exercise were reduced. The results demonstrate the antihypertensive efficacy of 'slow channel inhibitors' as represented by verapamil.

Effect on intra-arterial blood pressure of slow release metoprolol combined with placebo or chlorthalidone.

Thirty patients with essential hypertension participated in a double blind crossover trial in which they were randomly allocated to treatment with either once daily slow release metoprolol (200 mg) with placebo or once daily slow release metoprolol (200 mg) with chlorthalidone (25 mg). Ambulatory intra-arterial blood pressure was recorded continuously for 24-48 hours before treatment and two months after each change in regimen. The response of blood pressure and pulse rate to a standard exercise protocol that included supine rest and tilt, isometric, and dynamic bicycle exercise was measured during the same recording periods. Both treatments appreciably reduced blood pressure and pulse rate; mean daytime intra-arterial blood pressure was reduced from 174/95 mm Hg to 158/85 mm Hg by metoprolol plus placebo and to 143/78 mm Hg by metoprolol plus chlorthalidone. This reduction with the combined treatment was significantly greater than with metoprolol and placebo (p systolic = 0.001, p diastolic = 0.004). Mean night time pressures were reduced from 148/78 mm Hg to 139/75 mm Hg by metoprolol plus placebo and to 116/61 mm Hg by metoprolol plus chlorthalidone. Again the reduction in blood pressure was significantly greater with combined treatment (p less than 0.001) than with metoprolol plus placebo. Once daily slow release metoprolol is effective in controlling blood pressure, but this effect is greatly enhanced by the addition of a diuretic.

Prazosin alone and combined with a beta-adrenoreceptor blocker in treatment of hypertension.

We recorded intra-arterial ambulatory blood pressure in 13 patients with essential hypertension before and after long-term twice-daily prazosin therapy (mean dosage 13.8 mg, SD 4.2 mg). Nine other patients with essential hypertension inadequately controlled with beta-adrenoreceptor blocking drugs were studied before and after the addition of long-term twice-daily prazosin therapy (mean dosage 8.8 mg, SD 6.7 mg). Ten patients, responders from both groups, then received once-daily prazosin, and intraarterial monitoring was repeated for a third time. Circadian curves from pooled hourly data showed no significant reduction of intra-arterial ambulatory blood pressure with prazosin alone. There was a slight reflex tachycardia. Nine patients receiving combination therapy showed a daytime reduction in blood pressure averaging 24/6 mm Hg (p less than 0.001). Postural hypotension was recorded in both groups. Once-daily prazosin failed to control the blood pressure after 1700 h in the group of 10 patients defined as responders. Following combination therapy the blood pressure was reduced by 19/14 mm Hg at the peak of isometric hand grip and by 25/9 mm Hg on dynamic bicycle exercise. These data indicate that prazosin as an antihypertensive agent is best used in combination therapy with beta-adrenoreceptor blockade.

An intra-arterial profile of methyldopa.

The "Oxford" system for intra-arterial ambulatory blood pressure monitoring was used to monitor the blood pressure profile in 24 patients with essential hypertension who had received no therapy for 4 wk. The responses to tilt and isometric and dynamic bicycle exercise were recorded. Following the baseline study patients received methyldopa 125 mg t.i.d., which was titrated to a maximum of 500 mg t.i.d. according to blood pressure responses. The mean daily dosage was 1359 mg. Six weeks after the last dosage increment the experiment was repeated. Each patient was asked to take the total daily dosage once a day and the intra-arterial monitoring program was repeated after another 6 wk. Mean daytime intra-arterial blood pressure during three-times-daily dosing was reduced by 27/15 mm Hg; circadian curves were clearly separated during the day but not at night. Once-daily dosing did not control blood pressure as well. There was no evidence of postural hypotension and the absolute pressure response was lowered during both isometric and dynamic exercise. These results are comparable to those from similar studies with alpha- and beta-adrenoreceptor--blocking drugs.

[Therapy of hypertension with timolol, hydrochlorothiazide and amiloride]. / Hypertonietherapie mit Timolol, Hydrochlorothiazid und Amilorid.

The effectiveness of fixed combination tablets of timolol 10 mg. hydrochlorothiazide 25 mg and amiloride 2.5 mg (Moducrin) once daily in the control of blood pressure has been assessed in fully ambulant hypertensives by the technique of continuous intra-arterial recording. Highly significant blood pressure reduction (p less than 0.001) was obtained consistently throughout the whole day, confirming the potency and usefulness of the preparation for those patients who need more than one drug to control their blood pressure. 2. Blood pressure responses to both isometric and dynamic forms of exercise were also significantly lowered by combination therapy. 3. The addition of a diuretic to a beta-adrenoceptor blocker appears to be an advantage if the aim of treatment in hypertension is 24 h blood pressure control.

Assessment of the accuracy and role of self-recorded blood pressures in the management of hypertension.

Self-recording of the blood pressure by patients away from hospital or office ("home blood pressure") has been advocated as providing a better estimate of "true" blood pressure. The reliability of home blood-pressure recording has been assessed only by standard indirect methods which themselves are subject to considerable error and variability. The accuracy of self-recorded blood pressures was therefore assessed in 57 patients with essential hypertension by comparison with simultaneous measurements of clinic blood pressures and with intra-arterial blood pressures recorded at home and at hospital. Home systolic blood pressures showed good agreement with clinic and intra-arterial pressures, but home diastolic blood pressures overestimated intra-arterial pressures, as did clinic diastolic pressures. The clinic and home diastolic pressures showed good agreement. There was considerable variability in individual differences comparing the indirect and intra-arterial methods, though the two indirect methods showed much closer agreement. This study suggests that home blood pressures are as accurate as clinic readings but may be recorded more frequently and thus provide more useful information. Neither is likely to approximate the intra-arterial blood pressure.

The effect of once daily beta-adrenoceptor blocker-thiazide diuretic combination on the ambulatory blood pressure.

1 We have assessed the efficacy of Viskaldix, a combination of pindolol 10 mg and clopamide 5 mg using continuous intra-arterial ambulatory blood pressure monitoring. 2 Fourteen of the sixteen patients entered were studied on no therapy and following a minimum of 6 weeks at a constant dosage of Viskaldix. 3 Viskaldix produced a marked and consistent reduction of the blood pressure over the 24 h. The diurnal variation in the heart rate was decreased. 4 The results were compared with those of a similar study with once-daily pindolol where there was control during the day but not in the early morning when the blood pressures rose rapidly.

The effect of a combination of timolol, hydrochlorothiazide and amiloride on 24 hour blood pressure control using ambulatory intra-arterial monitoring.

1 The effectiveness of fixed combination tablets of timolol 10 mg, hydrochlorothiazide 25 mg and amiloride 2.5 mg (Moducren) once daily in the control of blood pressure has been assessed in fully ambulant hypertensives by the technique of continuous intra-arterial recording. Highly significant blood pressure reduction (P less than 0.001) was obtained consistently throughout the whole day, confirming the potency and usefulness of the preparation for those patients who need more than one drug to control their blood pressure. 2 Blood pressure responses to both isometric and dynamic forms of exercise were also significantly lowered by combination therapy. 3 The addition of a diuretic to a beta-adrenoceptor blocker appears to be an advantage if the aim of treatment in hypertension is 24 h blood pressure control.

A study of nadolol to determine its effect on ambulatory blood pressure over 24 hours, and during exercise testing.

1 The effect of once daily nadolol therapy in sixteen ambulant patients with essential hypertension has been closely assessed during exercise and over 24 h by continuous intra-arterial recording. 2 The drug was well tolerated and showed similar efficacy to other beta-adrenoceptor blocking agents. Whilst blood pressure reduction was observed throughout the whole day, it was not uniform and lost significance during the morning period when blood pressure levels were highest. 3 This provides further evidence that the antihypertensive action of a beta-adrenoceptor drug over 24 h cannot be predicted from its plasma half-life which, with regard to nadolol, is up to 24 h. 4 An explanation for the loss of blood pressure control during the morning may be that the rapid rise in blood pressure leading to the peak levels at this time may be mediated through alpha- rather than beta-adrenergic receptors at the periphery.

The role of a slow channel inhibitor, verapamil, in the management of hypertension.

1. The 'Oxford' system for continuous monitoring of the ambulatory blood pressure was used to assess the changes in blood pressure following therapy with the slow channel inhibitor, verapamil. 2. Sixteen patients were studied on no therapy and following a minimum of 6 weeks therapy (dose range 120-160 mg t.d.s.). During each study patients underwent standardized physological tests including tilt, isometric handgrip and dynamic bicycle exercise. 3. Verapamil was demonstrated to produce a consistent reduction of blood pressure over most of the 24 h period studied but this was most marked during the day. Heart rate was also reduced. 4. There was no postural hypotension and the absolute responses to dynamic and isometric exercise were reduced. 5. The results demonstrate the antihypertensive efficacy of 'slow channel inhibitors' as represented by verapamil.

The 24-hour ambulatory blood pressure profile with verapamil.

The blood pressure response in hypertensive subjects to chronic treatment with verapamil, a calcium antagonist (or, more precisely, a slow-channel inhibitor), was studied using the Oxford system for continuous monitoring of intraarterial blood pressure. Sixteen patients underwent continuous monitoring over a 48-hour period before and after at least 6 weeks of therapy (dose range 120-160 mg three times daily). Each monitoring period included physiologic tests designed to show the effects of different types of exercise. Verapamil produces a consistent reduction of blood pressure over 24 hours, but particularly during the day. Heart rate was similarly reduced. There was no evidence of postural hypotension, and the absolute responses to dynamic and isometric exercise were reduced. The degree of reduction of the blood pressure was consistent, suggesting that slow-channel inhibitors may be appropriate for antihypertensive therapy.