Left Ventricular Contractility Varies Directly with Blood Ionized Calcium

Lang, Roberto M.; Fellner, Susan K.; Neumann, Alexander; Bushinsky, David A.; Borow, Kenneth M.

doi:10.7326/0003-4819-108-4-524

Cited by 174 publications

(62 citation statements)

References 28 publications

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“…In six of eight patients, Ca was measured again approximately 2 hours after completion of each of the dialysis runs; there were no significant differences between the values obtained immediately after dialysis and those measured 2 hours later. 21 Arterial blood gases, electrolytes, creatinine, BUN, magnesium, and hematocrit, as well as body weight and heart rate did not differ among the three studies in each patient. Parathyroid hormone levels were markedly elevated in all but one patient (10.9±3.2 ng/ml, range 1.1-27.5 ng/ml; normal, <1.2 ng/ml).…”

Section: Biochemical Changesmentioning

confidence: 78%

“…Finally, it is possible that the peripheral vasculature in our patients was intrinsically abnormal and thus unable to undergo vasodilation in response to increased pressure and flow. Since total vascular resistance was at most only mildly elevated in our study population, and since we have previously shown that peripheral vasodilation can be easily obtained with nitroprusside in these patients, 21 this explanation seems unlikely. Several methodological issues should be addressed regarding the current study.…”

Section: Hemodynamic Changesmentioning

confidence: 79%

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Physiological mechanisms for calcium-induced changes in systemic arterial pressure in stable dialysis patients.

et al. 1989

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The mechanisms by which variations in blood ionized calcium (Ca 2+ ) influence systemic arterial pressures independent of changes in extracellular fluid volume, pH, and electrolytes are unknown. To study this issue, we dialyzed eight stable hemodialysis patients on three separate occasions during 1 week with dialysates differing only in calcium concentration. Ultrafiltration was adjusted to achieve the patient's estimated dry weight. Postdialysis Ca 2+ was measured, as were arterial blood gases, electrolytes, magnesium, blood urea nitrogen, creatinine, and hematocrit. Blood pressures and two-dimensional, targeted M-mode echocardiograms were recorded with the patient in the supine position after 15 minutes of rest. Postdialysis, three different levels of Ca 2+ were achieved. Other measured biochemical variables and body weight did not differ among the three study periods. Changes in Ca 2+ correlated directly with changes in systolic, diastolk, and mean blood pressures, left ventricular stroke volume, and cardiac output. In contrast, heart rate, left ventricular end-diastolic dimension, and total systemic vascular resistance were not altered significantly by changes in Ca 2+ . Thus, alterations in Ca 2+within the physiological range affect systemic blood pressure primarily through changes in left ventricular output rather than in peripheral vascular tone in stable dialysis patients. {Hyper-tension 1989;13:213-218) S ystemic arterial pressure is determined by the interaction between blood flow and resistance within the arterial tree. Changes in serum calcium concentration can theoretically alter either one or both of these hemodynamic variables. Prior clinical studies have suggested that hypercalcemia can cause a rise '-7 or no change 89 in systemic arterial pressure, whereas hypocalcemia is reported to reduce blood pressure.10 -12 Studies in patients undergoing hemodialysis have suggested that raising dialysate calcium concentration diminishes the typical fall in blood pressure that occurs during ultrafiltration and hemodialysis. 1314 However, the major methodological problem encountered in these prior investigations has been the difficulty in varying arterial blood ionized calcium (Ca physiological range in a stable and reproducible manner. Furthermore, interpretation of these results has been hampered by simultaneous changes in pH, plasma volume, and other electrolytes that may obscure the unique actions of calcium on the cardiovascular system. In the present study, systemic arterial blood pressures were measured in unanesthetized, stable hemodialysis patients immediately after dialysis on three separate occasions; dialysates differed only in calcium concentration. In this manner, the hemodynamic effects due to changes in Ca 2+ could be separated from those due to alterations in plasma volume, pH, magnesium, potassium, hematocrit, urea, and other nitrogenous compounds. Patients and MethodsThe study population consisted of eight patients (four women and four men; mean age, 45±5 years; range 32-80 years) with st...

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Section: Biochemical Changesmentioning

confidence: 78%

Section: Hemodynamic Changesmentioning

confidence: 79%

Physiological mechanisms for calcium-induced changes in systemic arterial pressure in stable dialysis patients.

et al. 1989

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“…Sin embargo, para complementar esta premisa, se realizaron experimentos en los que se evaluó la concentración de calcio intracelular por la administración de derivado carbamacepina-alquino en forma dependiente de la dosis, en ausencia y en presencia de nifedipino. Los resultados señalan que los niveles de calcio intracelular disminuyeron en presencia de nifedipino, lo que vuelve a corroborar que el efecto inducido por el derivado carbamacepina-alquino afecta indirectamente la concentración de este ión intracelular que está involucrado en cambios de la presión intraventricular, como lo señalan algunos investigadores (45,46).…”

Section: Discussionunclassified

Actividad inotrópica inducida por el derivado carbamacepina-alquino en un modelo de corazón aislado y perfundido a flujo constante

et al. 2011

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232Figueroa-Valverde L, Díaz-Cedillo F, López-Ramos M, et al. ARTÍCULO ORIGINALActividad inotrópica inducida por el derivado carbamacepina-alquino en un modelo de corazón aislado y perfundido a flujo constante Introducción. Existen pocos datos con respecto a los efectos de la carbamacepina y sus derivados en el aparato cardiovascular; además, el mecanismo molecular y su sitio de acción celular no son claros. Objetivo. Evaluar los efectos inducidos por el derivado carbamacepina-alquino sobre la presión de perfusión, la resistencia vascular y la presión ventricular izquierda. Materiales y métodos. Los efectos de la carbamacepina y del derivado carbamacepina-alquino sobre la presión de perfusión, la resistencia vascular y la presión ventricular izquierda fueron evaluados en un modelo de corazón aislado de rata (Langendorff).Resultados. Se encontró que: 1) el derivado carbamacepina-alquino (1x10 -9 mM) incrementa la presión de perfusión y la resistencia vascular en comparación con la carbamacepina (1×10 -9 mM); 2) los efectos del derivado carbamacepina-alquino (1×10 -9 -1×10 -4 M) sobre la presión intraventricular no fueron inhibidos por metoprolol o prazosina (1×10 -6 mM); 3); el nifedipino (1×10 -6 mM) bloquea los efectos ejercidos por el derivado carbamacepina-alquino (1×10 -9 -1×10 -4 M) sobre la presión intraventricular, y 4) el efecto del derivado de carbamacepina (1×10 -9 mM) incrementa la concentración de calcio intracelular a través del tiempo (3 a 18 minutos); sin embargo, en presencia de nifedipino (1×10 -6 mM), este efecto disminuye significativamente (p=0,005). Conclusiones. La actividad ejercida por el derivado carbamacepina-alquino sobre la presión de perfusión, la resistencia vascular y la presión intraventricular, involucra la activación del canal de calcio de tipo L, lo que trae como consecuencia indirecta cambios en los niveles de calcio intracelular y, subsecuentemente, induce un efecto inotrópico positivo.Palabras clave: carbamacepina, nifedipino, presión ventricular, resistencia vascular, corazón. Inotropic activity induced by carbamazepine-alkyne derivative in an isolated heart model and perfused to constant flowIntroduction. Few data exist with respect to the effects of carbamazepine and its derivatives at cardiovascular level; furthermore, the molecular mechanisms and cellular site of action are still unclear.Objective. The effects induced by carbamazepine-alquine derivative on perfusion pressure, vascular resistance and left ventricular pressure were evaluated. Materials and methods. The effects of carbamazepine and carbamazepine-alquine on the perfusion pressure, vascular resistance and left ventricular pressure were examined in isolated rat hearts (Langendorff model).Results. Four results were obtained: (1) The carbamazepine-alquine derivative [10 -9 mM] increased the perfusion pressure and vascular resistance in comparison with the carbamazepine [10 -9 mM]; (2) the effect of carbamazepine-alquine derivative [10 -9 -10 -4 mM] on left ventricular pressure not was inhibited by metoprolol or...

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“…First, bicarbonate may cause paradoxical intracellular acidification because of the increased generation of cell-permeant CO 2 by mass action effect on the carbonic acid equilibrium (38). Second, the increase in extracellular pH reduces ionized calcium concentration because of chelation by albumin (39), impairing myocardial contractility (40). Third, alkalinization may reduce tissue oxygen delivery by the Bohr effect on hemoglobin oxygen affinity.…”

Section: What Is the Most Effective Treatment For The Patient?mentioning

confidence: 99%

Lactic Acidosis in a Patient with Type 2 Diabetes Mellitus

Weisberg

2015

Clinical Journal of the American Society of Nephrology

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Lactic acidosis occurs when lactate production exceeds its metabolism. There are many possible causes of lactic acidosis, and in any given patient, several causes may coexist. This Attending Rounds presents a case in point. Metformin's role in the pathogenesis of lactic acidosis in patients with diabetes mellitus is complex, as the present case illustrates. The treatment of lactic acidosis is controversial, except for the imperative to remedy its underlying cause. The use of sodium bicarbonate to treat the often alarming metabolic derangements may be quite efficacious in that regard but is of questionable benefit to patients. Renal replacement therapies (RRTs) have particular appeal in this setting for a variety of reasons, but their effect on clinical outcomes is untested.

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Left Ventricular Contractility Varies Directly with Blood Ionized Calcium

Abstract: Variations in Ca2+ are directly correlated with clinically significant changes in myocardial contractility.

Cited by 174 publications

References 28 publications

Physiological mechanisms for calcium-induced changes in systemic arterial pressure in stable dialysis patients.

Physiological mechanisms for calcium-induced changes in systemic arterial pressure in stable dialysis patients.

Actividad inotrópica inducida por el derivado carbamacepina-alquino en un modelo de corazón aislado y perfundido a flujo constante

Lactic Acidosis in a Patient with Type 2 Diabetes Mellitus

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