Annotations

It is my practice to prescribe initially small doses of a mild diuretic-usually a thiazide (but bearing in mind these drugs’ diabetogenic qualities). The patient’s own observations as to effect will be carefully listened to and considered, as well as recording the response of the blood pressure and apex rate. If necessary, the dose can be cautiously increased. If the blood pressure still remains at a higher level than is desired it is my practice to “add on” small doses of either a beta-blocker (propranolol), or methyldopa, or clonidine, or rarely bethan- idine or guanethidine.

Again it must be emphasized that with older patients caution must be the keynote of therapy, and small doses must be used initially with frequent assessments made of the response obtained-say every three to seven days. These assessments will be made by the practice nurse, the doctor advising with regard to dosage, etc. Self-monitoring by the patient is probably by and large unsatisfactory, but may be possible with some.”

Once satisfactory control has been achieved it is essential to monitor the patient from time to time-say at three- or six- monthly intervals. As the years go by the older patients’ blood pressure will be found to drop, if therapy has been main- tained-presumably due to progressive myocardial degenera- tion. In such cases it will be essential to reduce the dosage of the treatment. (The onset of Addison’s Disease will also be discovered in the elderly-particularly if it is borne in mind and looked for!) Those patients taking methyldopa should have a periodical Coomb’s test and hemoglobin estimation. The urine, especially of those patients taking thiazides, should be periodically checked for sugar, and the electrolytes of any patient taking a diuretic should be borne in mind, as with the blood urea and uric acid. Infection and warm weather may dramatically lower the blood pressure, especially in the elderly, and this must not be lost sight of. Depression is a side- effect of both beta-blockers, methyldopa, bethanidine, and guanethidine and should be looked for. (I no longer use the rauwolfia alkaloids for this reason.) Clonidine may cause mental disturbance. Impotence with all these drugs may be a problem. The dangers of the beta-blockers in asthma, diabetes, and cardiac failure must not be overlooked, nor the fact that there is some evidence that they are contraindicated in generalized psoriasis and systemic lupus erythematosus.10 The onset of a paroxysmal heart block may pose problems, only soluble by the use of a pacemaker.

It should be re-emphasized that the drug regime should be kept as simple as possible, so that it will not only be understood but taken properly by the patient. There is

probably a place here for some of the combined preparations which many of us are normally loath to prescribe.

In conclusion, it may be said that hypertension is a disease par excellence of “the elderly.” Over the age of 65, the systolic blood pressure can cl imb dramatically.” The treatment of hypertension in such “elderly” patients is rewarding, both in terms of health and economics, provided that it is done with due care and caution. This treatment may be undertaken relatively simply and at comparatively small cost.

My thanks are due to Dr. H.G. Mather, M.D., F.R.C.P., of Bristol, for his help and advice with the preparation of this annotation.

D. T. C. Barlow, M.B., B.S., F.R.C.G.P., Orden of St. John General Practitioner

North Deuon, England 110 Boutport Street

Barnstaple, EX31 1TB England

REFERENCES

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

Jackson, G., Pierscianowski, T. A., Mahon, W., and Condon, J.: Inappropiate antihypertensive therapy in the elderly, Lancet 2:1317, 1976. Veterans Administration Cooperative Study Group on Antihypertensive Agents, J.A.M.A. 2t3:1143, 1970. Veterans Administration Cooperative Study Group on Antihypertensive Agents, J.A.&l.A. 202:1028, 1967.- Kanel. W. B., and Dawber. T. R.: Hvnertension as an

I -

ingredient of a cardiovascular risk profile, Br. J. Hosp. Med. 11508, 1974. Barham-Carter, A.: Hypotensive therapy in stroke survi- VOX?., Lancet 1:485, 1970. Flora, G. C., Baker, A. B., Lowenson, R., and Klassen, A. C.: Atherosclerosis in males and females, Circulation 38:859,1968. Gresham, G. A.: Is atheroma a reversible lesion? Athero- sclerosis 23379, 1976. I.&&man, A. W. D., and Sandler, G.: Hastening the control of blood-pressure by guanethidine, Lancet 1:668, 1965. Burn&ox, C. J., Rees, J. Russell, Wilson, R. S. E.: Pilot study of home measurement of blood pressure by hyper- ten&e patients, Br. Med. 5..3:80, 1975. Parsons, R. L.: Personal Communication. Guv’s Hosni- tal, London, 1977.

I

Hamilton, M., Pickering, G. W., Roberts, J. A. F., and Sowry, G. S. C.: The aetiology of essential hypertension. I. The arterial pressure in the general population, Clin. Sci. 13:11, 1954.

Pulmonary vascular effects of verapmil

Verapamil, a synthetic compound related to papaverine, is whether verapamil would depress the development of pulmo- currently under study as an anti-arrhythmic and antihyper- nary hypertension during chronic alveolar hypoxia. Therefore, tensive agent.’ It depresses transmembrane calcium influx in we exposed 250 gram male Sprague-Dawley rata to local cardiac2 and vascular smooth3 muscle, thereby resulting in altitude (1,600 M.) or to a simulated high altitude (5,500 M.) in membrane stabilization. We have shown that verapamil inhib- a hypobaric chamber for 20 days. Half the rats at each altitude its the pulmonary pressor response to acute alveolar hypoxia received 4 mg. verapamil in 0.5 C.C. saline intraperitoneally in isolated rat lungs and anesthetized dogs.4,5 We wondered twice a day and the other half received only saline. The degree

810 June, 1978, Vol. 95, No. 6 0002-8703/78/0695-0810$00.20/O 0 1978 The C. V. Mosby Co.

Annotations

Table I

Low Low High High altitude altitude altitude altitude saline verapamil saline verapamil

RV/T ratio 0.23 0.22 0.37 0.30 -+ 0.01 + O.bl * 0.01 t + O.Ol’f

No. rats 4 5 6 6

*Significantly different from high altitude saline group (P < 0.01). tSigni6cantly different from either low altitude group (P 4 0.01).

of hypoxic pulmonary hypertension was assessed by measur- ing the degree of right ventricular hypertrophy, using the ratio of the weight of the free wall of the right ventricle to the total ventricular weight8

Treatment with verapamil did not affect left ventricular weight, nor did it affect the hematocrit (low altitude 45 per cent, high altitude 63 per cent), suggesting that the hypoxic stimulus was the same in verapamil- and saline-treated groups. The values shown indicate that saline-treated high altitude rate developed more right ventricular hypertrophy than verapamil-treated animals. The smaller degree of right ventricular hypertrophy in high altitude rats treated with verapamil was presumably due to a lower level of hypoxic pulmonary hypertension. This finding is consistent with the observation that verapamil inhibits the pulmonary pressor response to acute alveolar hypoxia. The possibility of similar hemodynamic effects in man should be considered by physi-

Of why the two heart pumps are anatom ically united to form one heart

The heart is composed of two separate pumps which are separated.circulatorily by the pulmonary vascular system and the systemic vascular system. As indicated previously,’ the two separate pumps must be properly synchronized and integrated in their pumping of blood or the distribution of blood volume throughout the entire circulation would be seriously disturbed and either acute pulmonary congestion with acute pulmonary edema would result or the pulmonary vessels would become “emptied” of blood. To appreciate this fully, a previous publication should be studied closely.’

It is interesting to speculate why there is a two-pump cardiac system and why the two pumps are closely anatomi- cally intertwined to form one anatomic heart. This arrange- ment is an important, efficient, and desirable one. For exam- ple, were the right and left sides of the heart-the two pumps-completely separated, pulmonary congestion would suddenly occur if supraventricular or ventricular tachycardia developed in the independent and anatomically separate right heart while the left atrium and left ventricle continued to contract 70 or so t imes per minute. More blood would be ejected into the pulmonary vessels by the right pump than would be removed from these vessels by the left pump. Were the left atrium or ventricle to develop supraventricular or

cians using verapamil for its cardiotonic or anti-hypertensive effects.

Allan Davidson, M.D. Ivan McMurtry, Ph.D.

J.T. Reeves, M.D. CVP Research Laboratory

University of Colorado Medical Center

4200 East Ninth Ave. Denver, Colo. 80262

REFERENCES

5.

6.

Krikler, D.: Verapamil in cardiology, Europ. J. Cardiol. 2:3, 1974. Nayler, W. G., and Krikler, D.: Verapamil and the myocardium, Postgrad. Med. J. 50~441, 1974. Bohr, D. F.: Vascular smooth muscle updated, Circ. Res. 33:665, 1973. McMurtry, I. F., Davidson, A. B., Reeves, J. T., and Grover. R. F.: Inhibition of hsnoxic pulmonarv vasocon- striction by calcium antagon& in isolated-rat lungs, Circ. Res. 3899, 1976. Tucker, A., McMurtry, I. F., Grover, R. F., and Reeves, J. T.: Attentuation of hypoxic pulmonary vasoconstriction by verapamil in intact dogs, Proc. Sot. Exp. Biol. Med. 151:611, 1976. Abraham, A. S., Kay, J. M., Cole, R. B., and Pincock, A. C.: Haemodynamic and pathological study of the effect of chronic hypoxia and subsequent recovery of the heart and pulmonary vasculature of the rat, Cardiovasc. Res. 5:95, 1971.

ventricular tachycardia, more blood would be removed from the pulmonary vessels than would be pumped into them by the separate right heart pump, and the pulmonary vessels would become “dry” or essentially empty. These states would result in serious and acute circulatory disturbances and even death of the individual. On the other hand, with the right and left pumps joined anatomically as they are, both pumps respond essentially simultaneously to tachycardias or extra- systoles. Neither side of the heart can fibrillate or contract separately. This arrangement usually (I can think of excep- tions) assures a well-balanced circulation which is essential for a good circulatory state, as indicated elsewhere,‘, * even in the presence of arrhythmias which are initiated in either the right or left “pump.”

REFERENCES

George E. Burch, M.D. Tulane University School of Medicine

and Charity Hospital of Louisiana New Orleans, La.

1. Burch, G. E.: A primer of congestive heart failure, Smintrfleld, Ill., 1954, Charles C Thomas, Publisher.

2. Burch, G. E.: Congestive heart failure is.not due to low cardiac output per se, AM. HEART J. 94:269, 1977.

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