Thomas Dyckner

Ventricular extrasystoles and intracellular electrolytes before and after potassium and magnesium infusions in patients on diuretic treatment

Thirty-four patients suspected of being magnesium deficient were given intravenous infusions of potassium and magnesium. The muscle contents of sodium, potassium, magnesium, and chloride were determined by atomic absorption spectrophotometry on skeletal muscle samples obtained by percutaneous biopsies. The frequency of ventricular etopic beats (VEBs) was assessed from a 3-hour ECG tape recording before the infusions and after the completion of each infusion. The potassium infusions did not result in any changes in the cellular potassium content, nor in the frequency of VEBs. After the magnesium infusions, however, a significant increase was noted in the cellular potassium content and likewise a significant decrease in the frequency of VEBs. This emphasizes the importance of magnesium in potassium metabolism.

Potassium/magnesium depletion in patients with cardiovascular disease

Diuretic-induced deficiencies in potassium and magnesium can have significant implications for patients with cardiovascular disease. Hypokalemia, found in up to 50 percent of patients receiving thiazide therapy, is associated with a greater frequency of serious arrhythmias and increased mortality in patients with acute myocardial infarction. Hypomagnesemia has been identified in 42 percent of patients with hypokalemia, and below normal muscle magnesium levels have been found in 43 percent of congestive heart failure patients receiving diuretics. Magnesium is important for maintenance of cell potassium, and infusions of magnesium alone have increased muscle potassium and magnesium levels and significantly decreased the frequency of ventricular ectopic beats. It has been shown that both potassium and magnesium are conserved by potassium-sparing agents. Because serum and tissue magnesium levels are not correlated and correlations for potassium levels are weak, prevention of these electrolyte abnormalities is advised.

Intracellular Magnesium Loss After Diuretic Administration

SummaryDiuretic agents influence the renal handling of magnesium, causing increased losses of the ion. Continuing magnesium losses may, in the long term, result in a magnesium deficiency. 296 patients with congestive heart failure or arterial hypertension receiving long term diuretic therapy were studied by skeletal muscle biopsies to assess their magnesium status. 65% of the congestive heart failure patients and 42% of the patients with arterial hypertension were found to have subnormal values for skeletal muscle magnesium.Studies with the potassium-sparing diuretics amiloride, spironolactone and triamterene demonstrate that these drugs significantly increase the muscle magnesium content in patients on long term diuretic treatment for congestive heart failure and/or arterial hypertension — in addition to their well known positive effect on potassium balance.RésuméLes diurétiques agissent sur le métabolisme rénal du magnésium en accroissant son élimination. A long terme, la fuite rénale de magnésium peut avoir des conséquences cliniques. Chez 296 malades souffrant d’insuffisance cardiaque congestive ou d’hypertension artérielle et qui recevaient des diurétiques en traitement au long cours, on a pratiqué des biopsies musculaires pour y mesurer la concentration en magnésium. On a trouvé des valeurs proches de la normale chez 65% des insuffisants cardiaques et chez 42% des hypertendus.Dans le cadre de ces 2 pathologies, des études comparant des diurétiques d’épargne du potassium utilisés au long cours, amiloride, spironolactone et triamtérène, ont montré qu’ils augmentent significativement la concentration en magnésium au niveau musculaire. Ceci s’ajoute à leur effet déjà connu d’épargne du potassium.ZusammenfassungDiuretika beeinflussen die renale Behandlung von Magnesium und verursachen erhöhte Verluste dieses Ions. Kontinuierliche Magnesiumverluste können über längere Zeit einen Magnesiummangel ergeben. 296 Patienten mit Herzinsuffizienz oder arterieller Hypertonie, die eine diuretische Langzeittherapie erhielten, wurden mittels Skelettmuskelbiopsien untersucht, um ihren Magnesiumstatus zu bestimmen. Bei 65% der Patienten mit Herzinsuffizienz und bei 42% der Patienten mit arterieller Hypertonie wurden subnormale Magnesium werte für den Skelettmuskel gefunden.Untersuchungen mit den Kalium-sparenden Diuretika Amilorid, Spironolacton und Triamteren ergaben, daβ diese Pharmaka den Magnesiumgehalt des Muskels bei Patienten unter einer diureüschen Langzeittherapie wegen Herzinsuffizienz und/oder arterieller Hypertonie signifikant erhöhten — neben ihrer wohlbekannten positiven Wirkung auf die Kaliumbilanz.SommarioI diuretici influenzano il rimaneggiamento renale del magnesio, determinando maggiori perdite di questo ione. Una perdita continua di magnesio puó, a lungo termine, condurre ad una carenza di magnesio. Sono stati studiati 296 pazienti affetti da scompenso cardiaco congestizio o da ipertensione arteriosa, che ricevevano una terapia diuretica a lungo termine. Nello studio si è fatto uso di biopsie muscolari scheletriche allo scopo di valutare il loro patrimonio in magnesio. Si trovò che il 65% dei pazienti con scompenso cardiaco congestizio ed il 42% di quellt con ipertensione arteriosa presentavano concentrazioni di magnesio nella muscolatura scheletrica inferior! al normale.Studi eseguiti con diuretici risparmiatori di potassio quali amiloride, spironolattone e triamterene, dimostrano che questi farmaci aumentano in modo significativo il contenuto muscolare di magnesio in pazienti in terapia cronica con diuretici per scompenso cardiaco congestizio e/o per ipertensione arteriosa — oltre al loro ben noto effetto positivo sul bilancio del potassio.ResumenLos diuréticos influyen sobre el modo en que el riñón maneja el magnesio, dando lugar a mayores pérdidas del mismo. Las pérdidas continuadas de este ión pueden acabar a la larga en déficit del mismo. Se estudiaron 296 patientes afectos de insuficiencia cardiaca congestiva (ICC) o hipertensión arterial y sometidos a tratamiento diurético a largo plazo, mediante biopsias de müsculo esquelético para determinar su estado en lo relativo al magnesio, comprobándose que el 65% de los patientes con ICC y el 42% de los de hipertensión arterial presentaban valores subnormales de magnesio en el müsculo esquelético.Los estudios realizados con los diuréticos ahorradores de potasio (amilorida, espironolactona y triamterena) han demostrado que estos compuestos aumentan significativamente el contenido muscular de magnesio en los patientes sometidos a tratamiento diurético prolongado para la ICC y/o hipertension, además de sus beneficiosos efectos, ya conocidos, sobre et balance de potasio.ResumoOs agentes diuréticos influenciam o tratamento que os rins dão ao magnésio, causando perdas aumentadas do ion. Perdas continuadas de magnésio podem, a longo-prazo, resultar em deficiência de magnésio. Foram estudados 296 patientes com deficiência cardiaca congestiva ou com hipertensão arterial em tratamento de longa duração à base de diuréticos, por meio de biópsias do músculo esthado, com o objetivo de determinar-se o seu estado em relação à repleção de magnesio. Verificou-se valores sub-normais para a concentração de magnésio no músculo estriado em 65% dos patientes com deficiência cardiaca congestiva e em 42% dos patientes com hipertensao arterial.Há estudos com os diuréticos amiloride, spironolactone e triamterene — poupadores de potássio — demonstrando que estas drogas aumentam sensivelmente a concentração de magnésio no músculo em patientes de deficiência cardiaca congestiva ou de hipertensão arterial, sob tratamento de longa duração à base de diuréticos, além de demonstrarem o seu bem conhecido efeito positivo sobre o equilibrio do potássio.

Effects of spironolactone on serum and muscle electrolytes in patients on long-term diuretic therapy for congestive heart failure and/or arterial hypertension

SummaryThe effect of adding spironolactone (Aldactone) on muscle electrolytes was studied in 48 patients with arterial hypertension and/or congestive heart failure who had received conventional diuretic treatment, including a potassium supplement, for more than 1 year. After 6 months on spironolactone 100 mg/day as well as the original conventional diuretic therapy, there was a significant increase in both skeletal muscle potassium and magnesium. At the same time these parameters decreased in the control group. In the spironolactone group there was also a significant increase in the mean serum potassium and creatinine levels. There was a significant fall in blood pressure in the spironolactone-treated group.

Effects of peroral magnesium on plasma and skeletal muscle electrolytes in patients on long-term diuretic therapy

Twenty patients on long-term diuretic therapy for arterial hypertension and/or congestive heart failure were given a supplementary dose of 15 mmol magnesium aspartate hydrochloride per day for 6 months. Nineteen patients, fulfilling the same admission criteria as the treatment group, served as controls. The addition of magnesium aspartate hydrochloride resulted in a significant rise of the cellular potassium and magnesium content and in a significant decrease of both systolic and diastolic blood pressure. It is concluded that supplementation with magnesium aspartate hydrochloride may effectively prevent the diuretic induced disturbances of electrolyte balance.

Effects of triameterene on serum and skeletal muscle electrolytes in diuretic-treated patients

SummaryThe effects on plasma and skeletal muscle electrolytes of the combination of triamterene 37.5 mg and hydrochlorothiazide 25 mg daily were studied in 19 patients on prior long-term (>1 year) diuretic therapy for arterial hypertension and/or congestive heart failure. A further 20 patients fulfilling the same admission criteria were used as controls. Blood samples and skeletal muscle biopsies were taken before the study and after 6 months on therapy.The diuretic-treated group had a significant increase in skeletal muscle potassium and magnesium after 6 months on therapy as compared to the controls.Thus, the combination of triameterene and hydrochlorothiazide appeared effective in preserving the cellular content of potassium and magnesium on a long-term basis in the type of patient studied.

Initial serum potassium level, early arrhythmias and previous diuretic therapy in acute myocardial infarction

Unverferth DV, Magorien RD, Kolibash AJ, Lewis RP. Lykens M, Altschuld R, Baba N. Leier CV. Biochemical and histologic correlates of ventricular end-diastolic pressure. Int J Cardiol 1981; 1: 133142. Baandrup U. Endomyocardial biopsy in suspected cardiomyopathy a morphological and morphometric analysis. London: Ph.D. Thesis, 1979. Baandrup U. Olsen EGJ. Critical analysis of patients suspected of having cardiomyopathy. I. Morphological and morphometric aspects. Br Heart J 1981; 45: 475-486. Baandrup U, Florio RA, Rehahn M, Richardson PJ, Olsen EGJ. Critical analysis of patients suspected of having cardiomyopathy. II. Comparison of histology and clinicaI/haemodynamic information. Br Heart J 1981; 45: 487-493. Kuhn H, Breithardt G. Knieriem HJ et al. Die Bedeutung der endomyokardialen Katheter Biopsie fur die Diagnostik und die Beurteilung der Prognose der kongestiven Kardiopathie. Dtsch Med Wochenschr 1975; 100: 717-723. Baandrup U, Florio RA, Roters F, Olsen EGJ. Electron microscopic investigation of endomyocardial biopsy samples in hypertrophy and cardiomyopathy. Circulation 1981: 61: 12891298. Report of the WHO/ISCF task force on the definition and classification of cardiomyopathies. Br Heart J 1980; 44: 672-673. Circulation 1981; 64: 437A-438A. Baandrup U. Florio RA, Olsen EGJ. Do endomyocardial biopsies represent the morphology of the rest of the myocardium? A quantitative light microscopic study of single vs. multiple biopsies with the King’s bioptome. Eur Heart J. in press.