I. J. Med. Sc. Eighlh Series. Vol. 3. No. 8 August, 1970

HYPERALDOSTERONISM PRESENTING WITH REPETITIVE

STOKES-ADAMS A1[TACKS

By

P. MORTON and S. BEKHEIT

From the Cardiovascular Unit, Bel]ast City Hospital.

Summary

A N unusual case of primary hyperaldosteronism, associated with long. standing and severe hypertension, which presented with repetitive Stokes-Adams attacks caused by ventricular dysrhythmias, is repor-

ted. It was found that when the Q-Tc interval of the electrocardiogram was prolonged by more than fifty per cent ventricular dysrhythmia almost in- variably occurred. The close relationship of the onset of dysrhythmias to the increased Q-T interval rather than to the serum potassium levels is pointed out.

Introduction

Primary hyperaldosteronism usually presents during adult life with benign hypertension, with or without general symptoms of hypokalaemia such as periodic pareses, or polyuria (Conne t al., 1963). We report below a complicated and we believe unique case of Conn's syndrome which pre- sented with recurrent Stokes-Adams attacks caused by ventricular dysrhy- thmias. The case report includes biochemical and necropsy findings.

Case Report

A 51 year old housewife was admitted to the Intensive Coronary Care Unit on the 21st October, 1968, following three syncopal attacks. She had hypertension of at least fifteen years duration which had been treated intermittently with hypotensive drugs, not with diuretics. The clinic.al examination revealed hypertension (B.P. 200/ 130) and a grade It hypertensive retinopathy. A chest x-ray showed a normal heart shadow. The unique findings were shown in serial electrocardiograms recorded dur- ing further periods of unconsciousness which will be discussed in detail below. An electrolyte block shortly after admission suggested the .possibility of hypokalaemia due to hyperaldosteronism, and the relevant investigations were commenced.

Results

Serum K 1.6 meq./litre; serum Na 120 meq./litre; C02cp 30 meq./litre; serum chloride 76 meq./li tre and blood urea 52 mgs. per cent.

Plasma aldosterone 25.16 ug./100 ml. (normal <18). Plasma renin 90 and 83 units/litre (normal 4--20). Urinary aldosterone 68 and 43 ugs./24 hours (normal 20). A modified sodium and potassium balance study did not differentiate between primary and secondary hyperaldosteronism.

357

358 IRISH JOURNAL OF MEDICAL SCIENCE

An I.V.P. showed kidneys of normal size, shape and position wilh good excretion on both sides.

A left adrenal venogram showed a normal vascular pattern.

A glucose tolerance curve demonstrated mild to moderate carbohydrate intolerance.

Serum S.G.O.T. and L.D.H. were normal on several occasions.

Serum protein electrophoresis, serum Ca., P., Mg., and plasma cortisol were normal.

Treatment was commenced with spironolactone and oral potassium sup- plements. This produced only a slight fall in blood pressure, but the serum potassium was maintained at normal levels. On 16th January, 1969 ex- ploratory laparotomy was carried out (before the results of plasma renin and aldosterone assays were available). A total left adrenalectomy and a sub-total right adrenalectomy were performed. No tumour was palpated in either gland, but small nodules were seen macroscopically in both glands. Nineteen hours after operation the patient suddenly developed signs of cerebral infarction and died shortly afterwards.

Necropsy

Adrenals : The zona glomerulosa of both glands was broad and hyl;erplastic. It sent several tongue like extensions into the substance of the cortex. Numerous small intra-cortical nodules were also present. The appearances were those of primary hyperaldosteronism due to bilateral hyperplasia of the zona glomerulosa with adreno- cortical nodules (Brown et al. 1968). There was generalised arteriopathy particularly affecting the kidneys, the adrenals and the brain. The left ventricle was hypertro- phied and there were areas of ischaemic fibrosis throughout the myocardium.

Electrocardiographic Metabolic Changes

The patient's course was interrupted by more than twenty episodes of syncope caused by ventricular dysrhythmias and several paroxysms of nodal tachycardia. All the ventricular dysrhythmias were terminated by intra- venous potassium (but not by I.V. Xylocaine). The significant electrocar- diographic features were prolonged Q-T intervals and recurrent ventricular ectopic rhythms. The latter was the mechanism of the syncopal attacks. Figure I A. shows the electrocardiogram shortly after admission and before treatment, with the prolonged Q-T interval (0.6 secs,-normal 0.39 secs.). Figure I B.C.D.E. illustrate the various ectopic rhythms. B shows ventricu- lar tachycardia and C ventricular flutter with spontaneous restoration of normal sinus rhythm. D demonstrates the termination of ventricular flutter with intravenous potassium therapy. Note the hyperkalaemic T waves in the last two complexes. E shows a paroxysm of nodal tachycardia and F normal sinus rhythm with only slight prolongation of the Q-T interval (0.48 secs.--normal 0.39 secs.) and a normal serum potassium.

The Q-T interval was measured in ventricular complexes occurring im- mediately before the onset of each episode of ventricular dysrhythmia, and of nodal tachycardia, as well as during periods of sinus rhythm when the

STOKES-ADAMS ATTACKS 359

Fig. l--Ventricular dysrhythmias and Q-T interval.

A. Sinus rhythm with marked �9 of the Q-T i~terval (0.6 secs.).

B. Episode of ventricular tachycardia (Rate 200:min.).

.~.i~.': ~ : : . ~ 2 . . i :~ ~. ~ .:.....s I{.: :. i -,: - +. , : . : . . i . ,.: i:. !.. i ~ , { ~ ;~:~i-~.: :, ~.i : ~: : ~ i i ~ ~.:: . i:~i:, i , : ' , ::: ===================== : i : v ! t

2:: :,' " ,~ ~ i ~ ~ :.~' :~ " " i ~

C. Rapid regular ventricular rhythm (Flutter~Rate 220/rain.).

D. Termination of ventricular flutter following i.v. potassium.

E. Nodal

~ :; j:~::~ i "gs ?j: ~'~,. :!~-~ ,', i i / ~ : ~. ; ~ ' : - ~ l - , , ' e T ~ ] 1 ~'~" ."~ I~!:':"s ~L"IF ; ~ ~ " ~ " ~ - ' ~ ' ,~ ~-~llv~ ~

- \ I!

,~ ~ ? 7: :,;:. s : ,,, .~".',,, : c , " .~ ~ 2~,,,,,:~g.~ ~ z ~:~:~',": ? g,~. . :z : 2 ,,': .~ ,'," �9 ~2d ; ,~,'i ".I ~ �9 .. i . : . .~ : ~ .,. ~ : 7.1 : . g2 .: ..." ~ .~ ~ ,?~ " .~ :

tachycardia (Rate 150,min.).

F.

1 ~ �9 . , . �9 I - . ~ . ~*~

Normal sinus rhythm. Q-T interval 0.48 secs.

360 IRISH JOURNAL OF MEDICAL SCIENCE

serum potassium was normal, and when it was low. The Q-T interval was prolonged in all instances compared with normal values (Ashman and Hull, 1945). The percentage increase in Q-Tc interval was calculated and plotted against the serum potassium (estimated at 10.00 a.m. on the corresponding

..J

n- klJ p- Z

I

O

z

uJ co <:

c) Z

80

70

6o

50

40

30

20

10

&&

A A

&A

A k & A

�9 V.Flutter

A SintJs I~hythym

�9 Nodal T~lch~ardicl

o S~nus Rhytt~

�9 &

A&

~ A

o o o

o

O

O

! 2 3 ,4 5 b

mEq / L

P O T A S S t U M L E V E L IN S E R U M

Fig. I I - -The relation of the degree of prolongation of the Q-Tc intervals to the onset of ventricular dysrhythmias.

Note the occurrence of ventricular flutter when the percentage increase in Q-Tc in- terval exceeds fifty per cent and sinus rhythm with low petassium levels (mean 2,6 rags. per cent) when percen.tage increase in Q-Tc interval was less than fifty per cent of normal.

STOKES-ADAMS ATTACKS 361

day). The results are shown in Figure II which illustrates the relationship between the occurrence of ventricular dysrhythmia and the increased Q-Tc interval. In sixteen out of seventeen recorded instances of ventricular flutter the Q-Tc interval immediately before the onset was prolonged by more than fifty per cent, while serum potassium on the corresponding days varied between 1.6 and 3.0 mgs. per cent (mean 2.8 mgs. per cent). However, on six other occasions the serum potassium was less than 3.0 mgs. per cent (mean 2.6 mgs. per cent) but in each instance the Q-Tc interval was in- creased by less than fifty per cent, and the heart remained in sinus rhythm.

Comment

The serum potassium can be within the normal range in patients who are severely depleted of potassium (Stock, 1969) and it is generally accepted that the electrocardiographic disturbances of repolarisation reflect more accurately intracellular potassium depletion (Barker, 1952). In our patient the onset of ventricular dysrhythmia was closely related to the duration of the Q-Tc interval and not to the serum potassium level. The Q-Tc interval was always prolonged, but when this was increased by more than fifty per cent, ventricular tachycardia or ventricular flutter almost invariably fol- lowed. The probable explanation for these findings is the phenomenon of hysteresis described by Lepeschkin (1950).

Ventricular dysrhythmias are well recognised complications of potas- sium depletion resulting from chronic diarrhoea, or prolonged therapeutic diuresis. They have not been reported previously however in patients with hypokalaemia due to either primary or secondary hyperaldosteronism.

Rcferences

Ashman, R. and Hull, E., "'Essent!als of Electrocardiography". 2nd Ed., New Yo:k, The MacMillan Co. 1945.

Barker, J. M., "The Unipolar Electrocardiogram". Appleton-Century-Crofts, Inc., New York. 1952.

Brown, J. J., Davies, D. L., Eraser, R., Robertson, J. I. S.. Chi'nn, R. H., Dusterdieck, G., Lever, A. F., Tree, M. and Wiseman, A., Lancet 1%8, ii, 55.

Conn, J. W., Knopf, R. 1~. and Nesbit, R. M., J. Amer. Med. Ass. 1963 a, 183, 871.

Lepeschkin, E., "Modern Electrocardiography". Vol. I. Baltimore Williams and Wilkins, 1950.

Stock, J. P. P., "'Diagnosis and Treatment of Cardiac Arrhythmias". Butterworth, 1%9.

Acknowledgments

The authors wish to thank Professor J. J. Brown of the M.R.C. Blood Pressure Research Unit, Western Infirmary, Glasgow, for undertaking the plasma renin and aldosterone assays; also Professor T. SymingtorL and Dr. Munro Neville of the De- partment of Pathology, Royal Infirmary, Glasgow, for the histological report on the adrenal tissue.