digitoxin and Ischemia

Colon ischemia (CI) is the most common form of ischemic injury of the gastrointestinal tract. Determining the precise incidence of CI is a challenging task, because of its often brief, mild nature, and frequent spontaneous resolution, as well as its misdiagnosis as other diseases. While many underlying disease conditions may predispose patients to CI, an important and possibly overlooked etiology is that of pharmacologically induced alterations of colonic blood flow. This review details the pharmacologic agents known to be associated with CI; when possible, their mechanisms of action are described. The aim of this paper is to highlight this often unrecognized cause of CI, thereby helping physicians to be aware of the association, to recognize its occurrence promptly, and to possibly reduce morbidity and mortality.

Topics: Anti-Bacterial Agents; Antineoplastic Agents; Appetite Depressants; Colon; Colonic Neoplasms; Constipation; Digitalis; Humans; Ischemia; Nasal Decongestants

Topics: Age Factors; Aged; Blood Pressure; Body Weight; Clinical Trials as Topic; Digitoxin; Female; Headache; Heart Diseases; Heart Rate; Heart Valve Diseases; Humans; Ischemia; Male; Middle Aged; Myocardial Infarction; Nausea; Pulmonary Heart Disease; Tachycardia, Paroxysmal

Nonocclusive mesenteric ischemia is a rare but serious disorder with a high mortality rate; causal factors include cardiac glycosides, digoxin, and digitoxin in addition to severe hypotension, decompensated heart failure, and septic shock.. We present a patient with digitoxin intoxication who died from autopsy-confirmed ischemic gangrenous colitis.. Despite the frequent occurrence of intoxication with cardiac glycosides nonocclusive mesenteric ischemia is a rare event. However, it should always be included as a differential diagnosis of diffuse abdominal pain in patients treated with cardiac glycosides.

Topics: Aged; Aged, 80 and over; Cardiotonic Agents; Digitoxin; Female; Gangrene; Humans; Ischemia; Mesentery

Topics: Acetyldigitoxins; Aged; Aged, 80 and over; Colitis; Digitoxin; Female; Humans; Immunoglobulin Fab Fragments; Ischemia

To characterize any digitalis-induced differences in intestinal blood flow autoregulation, we studied the circulatory responses of the rat intestine in control (n = 7) and chronically digitalized (n = 7) animals. Data were generated from denervated isoperfused small intestinal preparations. Arterial pressure, venous pressure, and oxygen consumption were continuously monitored. Determinations of intestinal blood flow allowed calculation of mesenteric vascular resistance and oxygen consumption. Animals underwent stepwise reductions in arterial pressure and acute venous hypertension (10 to 15 mm Hg). There were no differences in baseline hemodynamic or metabolic parameters in control (C) or digitalized (D) animals. Blood flow and oxygen consumption were autoregulated in both C and D rats until perfusion pressure decreased below 50 mm Hg. The response to acute venous hypertension was different. In D rats, venous hypertension resulted in increased vascular resistance (millimeters of mercury per milliliter per minute per 100 gm) [0.89 +/- 0.05 to 0.97 +/- 0.07; p less than 0.05], whereas C rats demonstrated no change [0.92 +/- 0.08 to 0.95 +/- 0.09]. The decrease in oxygen consumption in D rats (-14%) was slightly but significantly greater than that observed in C rats (-9%). Digitalized rats demonstrated a heightened myogenic response to acute venous hypertension with deleterious effects on vascular resistance and oxygen consumption. This reaction was intrinsic to the mesenteric circulation and not mediated by sympathetic nerves or central reflexes. Nonocclusive mesenteric ischemia in digitalized patients may reflect a similar abnormal response to the acute increases in portal pressure accompanying cardiac failure.

Topics: Animals; Blood Pressure; Digitalis; Digoxin; Homeostasis; Humans; Intestine, Small; Ischemia; Male; Mesenteric Arteries; Mesenteric Veins; Oxygen Consumption; Plants, Medicinal; Plants, Toxic; Rats; Rats, Inbred Strains; Splanchnic Circulation; Time Factors; Vascular Resistance

After presenting the case of a 70 year old woman who presented a massive mesenteric infarction as a result of non-occlusive intestinal ischaemia ( NOII ), the authors review the principal features of this particular form of intestinal ischaemia. This condition is seen principally in elderly people with a syndrome of low cardiac output, resulting in marked mesenteric vasoconstriction. It is a complication of either severe decompensated heart disease treated with digitaloids or to a state of hypovolaemic or septic shock. The diagnosis of NOII should be suggested by the combination of abdominal signs with a state of shock and/or treated heart disease. The diagnosis is confirmed by selective mesenteric arteriography which reveals a patent but spastic vessel. The treatment is initially medical, consisting of the correction of haemodynamic disturbances and the in situ injection of vasodilator products, which may need to be completed by a surgical operation. However, the prognosis of NOII remains serious, particularly because of the frequent delay in making the diagnosis.

Topics: Acetyldigitoxins; Acute Disease; Aged; Cardiac Glycosides; Digitoxin; Female; Humans; Intestines; Ischemia

The effect of prophylactic digitalization on the development of left ventricular hypertrophy was studied in adult rats. Digitoxin, 0.1 mg/100 g body wt or solvent was given daily for 1 wk prior to either aortic constriction or sham operation and was continued until the animals were killed, either 1 or 4 wk after surgery. A hemodynamic study was done in those animals killed 1 wk after surgery; hearts of all animals were examined for evidence of myocardial hypertrophy. Constriction of the ascending aorta had no significant effect on cardiac output but did reduce peak flow velocity and flow acceleration. An increase in left ventricular mass, RNA, and hydroxyproline was found in the animals with aortic constriction. Digitoxin treatment did not alter peak flow velocity or flow acceleration, but did significantly increase isovolumic (dP/dt)P-1. Digitoxin had no effect on body weight, heart weight, RNA, or hydroxyproline in either the sham-operated animals or in the animals with aortic constriction. Therefore, despite plasma digitoxin levels sufficient to affect myocardial contractility, left ventricular hypertrophy still developed after aortic constriction.

Topics: Animals; Aorta; Blood Pressure; Cardiomegaly; Collagen; Coronary Circulation; Digitoxin; Female; Heart; Hydroxyproline; Ischemia; Myocardial Contraction; Myocardium; Rats; RNA

Research in recent years has shown that under certain conditions digitalis has a strong vasoconstrictive effect in the splanchnic region. This may imply that in cases of mesenteric ischaemia, digitalization may inhibit a collateral circulation necessary for restoration of the intestinal function. In this investigation the effect of digitoxin on the exchange circulation of the small bowel mucosa was studied in rats with induced regional ischaemia of the intestine. On analysis 30 min after establishment of the ischaemia a statistically significant negative effect of digitoxin was observed.

Topics: Animals; Digitoxin; Drug Evaluation, Preclinical; Intestinal Diseases; Intestinal Mucosa; Intestine, Small; Ischemia; Male; Rats

It is the bicentennial anniversary of the introduction of digitalis into medicine. Digitalis is one of the most important drugs ever discovered, and after two centuries, it is still the most widely used drug in cardiology. However, it was at one time so badly abused that for nearly a century it was almost abandoned. Early in this century, the valuable effects of digitalis were once again recognized and extended. The molecular basis of action has been defined and now methods are available to detect early toxicity. Recent advances in combating toxic effects show considerable promise. Skillful administration of the drug, using purified standard tablets, careful monitoring by clinical electrocargiography, and analytical methods can secure the maximun benefits with the minimum degree of toxicity.

Topics: Arrhythmias, Cardiac; Digitalis Glycosides; Digitoxin; Digoxin; England; Heart; Heart Failure; History, 18th Century; Humans; Intestinal Absorption; Intestines; Ischemia; Pacemaker, Artificial; Suicide; Tablets; Time Factors

Topics: Aged; Blood Urea Nitrogen; Body Weight; Digitalis; Diuretics; Female; Furosemide; Heart Failure; Hematocrit; Humans; Hydrochlorothiazide; Infarction; Ischemia; Male; Mesenteric Arteries; Mesenteric Vascular Occlusion; Middle Aged; Organomercury Compounds; Plants, Medicinal; Plants, Toxic; Sodium Chloride Symporter Inhibitors; Triamterene

Topics: Acute Disease; Bundle-Branch Block; Computers; Coronary Vessels; Diagnosis, Computer-Assisted; Diagnosis, Differential; Diaphragm; Digitalis; Electrocardiography; Heart Block; Heart Diseases; Heart Rate; Heart Ventricles; Humans; Hypertrophy; Infarction; Ischemia; Mathematics; Mitral Valve; Myocardial Infarction; Pericarditis; Plants, Medicinal; Plants, Toxic; Potassium

Topics: Aged; Atrial Fibrillation; Cardiomyopathies; Diagnosis, Differential; Digitalis; Electrocardiography; Geriatrics; Heart Diseases; Heart Failure; Heart Valve Diseases; Humans; Hypertension; Ischemia; Mitral Valve Insufficiency; Phytotherapy; Plants, Medicinal; Plants, Toxic; Ventricular Fibrillation