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Biomedical subjects

U Elkayam

Publications and source records attributed to U Elkayam.

At least 19 recordsLinked to original sources
PubMed2000

Intravenous nesiritide, a natriuretic peptide, in the treatment of decompensated congestive heart failure. Nesiritide Study Group.

BACKGROUND: Intravenous infusion of nesiritide, a brain (B-type) natriuretic peptide, has beneficial hemodynamic effects in patients with decompensated congestive heart failure. We investigated the clinical use of nesiritide in such patients. METHODS: Patients hospitalized because of symptomatic congestive heart failure were enrolled in either an efficacy trial or a comparative trial. In the efficacy trial, which required the placement of a Swan-Ganz catheter, 127 patients with a pulmonary-capillary wedge pressure of 18 mm Hg or higher and a cardiac index of 2.7 liters per minute per square meter of body-surface area or less were randomly assigned to double-blind treatment with placebo or nesiritide (infused at a rate of 0.015 or 0.030 microg per kilogram of body weight per minute) for six hours. In the comparative trial, which did not require hemodynamic monitoring, 305 patients were randomly assigned to open-label therapy with standard agents or nesiritide for up to seven days. RESULTS: In the efficacy trial, at six hours, nesiritide infusion at rates of 0.015 and 0.030 microg per kilogram per minute decreased pulmonary-capillary wedge pressure by 6.0 and 9.6 mm Hg, respectively (as compared with an increase of 2.0 mm Hg with placebo, P<0.001), resulted in improvements in global clinical status in 60 percent and 67 percent of the patients (as compared with 14 percent of those receiving placebo, P<0.001), reduced dyspnea in 57 percent and 53 percent of the patients (as compared with 12 percent of those receiving placebo, P<0.001), and reduced fatigue in 32 percent and 38 percent of the patients (as compared with 5 percent of those receiving placebo, P<0.001). In the comparative trial, the improvements in global clinical status, dyspnea, and fatigue were sustained with nesiritide therapy for up to seven days and were similar to those observed with standard intravenous therapy for heart failure. The most common side effect was dose-related hypotension, which was usually asymptomatic. CONCLUSIONS: In patients hospitalized with decompensated congestive heart failure, nesiritide improves hemodynamic function and clinical status. Nesiritide is useful for the treatment of decompensated congestive heart failure.

Atrial Natriuretic Factor↗
PubMed2000

Effect of mibefradil, a T-type calcium channel blocker, on morbidity and mortality in moderate to severe congestive heart failure: the MACH-1 study. Mortality Assessment in Congestive Heart Failure Trial.

BACKGROUND: Calcium antagonists have proved disappointing in long-term congestive heart failure (CHF) studies. Mibefradil, a new calcium antagonist that selectively blocks T-type calcium channels, has been shown to be an effective antihypertensive, antianginal, and anti-ischemic agent, and because of its different mechanism of action, it may be beneficial as adjunct therapy in CHF patients. METHODS AND RESULTS: This multicenter, randomized, double-blind study compared mibefradil with placebo as adjunct to usual therapy in 2590 CHF patients (NYHA class II to IV; left ventricular fraction <35%). The initial 50-mg daily dose of mibefradil was uptitrated to 100 mg after 1 month and continued up to 3 years. Patients were monitored at 1 week; 1, 2, and 3 months; and every 3 months thereafter. All-cause mortality, cardiovascular mortality, and cardiovascular morbidity/mortality were analyzed by use of the log-rank test (alpha=0.05). Substudies included exercise tolerance, plasma hormone and cytokines, echocardiography, and quality of life. Total mortality was similar between mibefradil- and placebo-treated patients (P=0.151). The 14% increased risk of mortality with mibefradil in the first 3 months was not statistically significant (P=0.093). Treatment groups had similar cardiovascular mortality (P=0.246), cardiovascular morbidity/mortality (P=0.783), and reasons for death or hospitalization. Patients comedicated with mibefradil and antiarrhythmics (class I or III), including amiodarone, had a significantly increased risk of death. Substudies demonstrated no significant differences between treatments. CONCLUSIONS: When used as adjunct therapy, mibefradil did not affect the usual outcome of CHF. The potential interaction with antiarrhythmic drugs, especially amiodarone, and drugs associated with torsade de pointes may have contributed to poor outcomes early in the study.

Aged↗
PubMed2000

Unstable angina during pregnancy in two patients with premature coronary atherosclerosis and aortic stenosis in association with familial hypercholesterolemia.

Obstructive atherosclerotic coronary artery disease is uncommon in women during childbearing age, and the occurrence of myocardial ischemia during pregnancy has therefore been anecdotal. Two young patients with premature coronary artery disease in association with familial hypercholestrolemia had unstable angina in the second trimester of pregnancy. Workup revealed coronary artery disease and aortic stenosis. One patient opted for abortion at the twentieth week of gestation, and the other decided to continue pregnancy and was delivered by cesarean at 28 weeks' gestation. Coronary artery bypass grafting was performed after pregnancy in both patients. In addition, one of the patients underwent aortic valve replacement, and other had replacement of the narrowed ascending aorta with uneventful recovery. Our report describes an uncommon presentation of unstable angina during pregnancy in 2 young women with premature coronary artery disease and aortic valvular and supravalvular stenosis as a result of familial hypercholesterolemia. The management of these conditions during pregnancy is influenced by the effects of available therapeutic modalities on both maternal and fetal outcome.

Adolescent↗
PubMed1999

Double-blind, placebo-controlled study to evaluate the effect of organic nitrates in patients with chronic heart failure treated with angiotensin-converting enzyme inhibition.

BACKGROUND: Organic nitrates are widely used in the treatment of chronic heart failure (CHF). No information, however, is available regarding their effect in patients already treated with ACE inhibitors. METHODS AND RESULTS: In a randomized, double-blind, crossover design, we studied the effects of high-dose (50 to 100 mg) transdermal nitroglycerin (NTG) and placebo given daily for 12 hours in 29 patients with CHF (NYHA functional classes II to III). Exercise time (4 hours after patch application) showed a progressive improvement during NTG administration, with an increase of 38+/-35 seconds (9+/-7%) at the end of the first month (P=NS), 76+/-28 seconds (16+/-6%) at the end of the second month (P=0.01), and 117+/-34 seconds (27+/-6%) at the end of the third month (P=0.003). No significant change was seen during placebo administration (12+/-20, 5+/-26, and 19+/-28 seconds, all P=NS). Exercise time 8 hours after NTG application measured at 3 months was also significantly longer, with a difference of 87+/-28 seconds (P=0.006), but not with placebo (23+/-36 seconds, P=0.53). Assessment of quality of life and need for additional diuretics or hospitalizations for CHF failed to demonstrate a significant difference between the 2 treatment periods. In contrast, NTG decreased left ventricular end-diastolic (-2.1+/-0.1%, P<0.05) and end-systolic (-3.2+/-1.3%, P<0.05) dimensions and augmented LV fractional shortening (24.7+/-10.5%, P<0.03). The effect of placebo on these parameters was not statistically significant. CONCLUSION: High-dose nitrate therapy significantly improves exercise tolerance and left ventricular size and systolic function in patients with chronic, mild to moderate CHF already treated with ACE inhibitors. These findings support the role of organic nitrates as an adjunctive therapy to ACE inhibitors in patients with chronic CHF.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

A randomized trial of ecadotril versus placebo in patients with mild to moderate heart failure: the U.S. ecadotril pilot safety study.

OBJECTIVE: To determine the short-term safety and tolerability of the addition of ecadotril to conventional therapy in patients with mild to moderate heart failure. METHODS: Fifty ambulatory patients, 18 to 75 years of age, with mild to moderate heart failure, left ventricular ejection fraction </=35%, taking stable doses of angiotensin-converting enzyme inhibitor, diuretics, and optionally digoxin were enrolled in a randomized, double-blind, placebo-controlled dose-escalation study of ecadotril 50 to 400 mg twice daily versus conventional therapy alone. RESULTS: No increases in deaths, serious adverse events, or dropouts from adverse events were observed for the ecadotril group compared with placebo. The serum measures of neurohormonal activation were highly variable. Changes in signs and symptoms of heart failure, New York Heart Association class, and patient self-assessment of symptoms were not observed with ecadotril therapy; however, the study was not designed to detect differences in these parameters. CONCLUSION: In this small pilot study, ecadotril in doses of 50 to 400 mg twice daily was generally well-tolerated and without severe short-term adverse effects in patients with mild to moderate heart failure. Evaluation of the clinical efficacy and long-term safety of ecadotril and other neutral endopeptidase inhibitors in patients with heart failure requires further study.

Adolescent↗
PubMed1999

Favorable response of Eisenmenger syndrome to inhaled nitric oxide during pregnancy.

OBJECTIVE: Our goal was to evaluate the effectiveness of therapy with a specific pulmonary vasodilator, nitric oxide, in a woman with Eisenmenger syndrome during pregnancy. STUDY DESIGN: Eisenmenger syndrome consists of a congenital communication between the systemic and pulmonary circulation with secondary pulmonary hypertension causing reversal of flow through the shunt. Maternal morbidity is approximately 50% with the greatest risk of death being in the peripartum period. Pharmacologic therapy to relieve worsening pulmonary hypertension is confounded by the undesired effects of vasodilators on the systemic circulation. Therapy with a specific pulmonary vasodilator, nitric oxide, was attempted. RESULTS: A 27-year-old woman with Eisenmenger syndrome at 36 weeks' gestation was treated with inhaled nitric oxide during the second stage of labor and the postpartum period when she experienced progressive refractory hypoxemia. Administration of nitric oxide was followed by improved oxygenation and lowering of pulmonary artery pressures. A brief episode of methemoglobinemia responded to lowering of the nitric oxide concentration and administration of intravenous methylene blue. Nitric oxide was discontinued after 48 hours. The patient died 2 days later despite continued vasodilator therapy including intra-pulmonary artery prostacyclin. CONCLUSION: Inhaled nitric oxide can be used to correct the hypoxemia of Eisenmenger syndrome. Nitric oxide inhalation is easily performed, and pulmonary vasodilatory effects commence within minutes after administration.

Administration, Inhalation↗
PubMed1998

Renal circulatory effects of adenosine in patients with chronic heart failure.

OBJECTIVES: We sought to study the renal circulatory effects of adenosine in patients with chronic congestive heart failure (CHF). BACKGROUND: Renal blood flow (RBF) is often reduced in patients with chronic CHF and may lead to decreased renal function. The cause of reduced RBF is multifactorial and involves systemic as well as local vasoregulatory mechanisms. Stimulation of renal adenosine A1 receptors in animal models has resulted in a significant vasoconstriction of afferent and efferent glomerular arterioles and deterioration of renal function. Although adenosine serum levels have been shown to be elevated in patients with CHF, their effect on the renal circulation in this patient population has not been studied. METHODS: Nine patients with CHF from left ventricular systolic dysfunction were studied. The effects of adenosine at a dose of 10(-5) mol/liter infused directly into the main renal artery on heart rate, renal artery blood pressure, renal artery cross-sectional area (measured by intravascular ultrasound), renal Doppler blood flow velocity (measured by a Doppler flow wire in the renal artery), RBF and renal vascular resistance (RVR) were evaluated. RESULTS: Infusion of adenosine resulted in no significant effect on heart rate or renal artery blood pressure but caused a substantial increase in RVR (11,204 +/- 1,469 to 31,494 +/- 3,911 dynes x s x cm(-5), p = 0.0005), which led to a marked fall in RBF in every patient (mean values 376 +/- 36 to 146 +/- 22 ml/m2, p = 0.0002). These changes in RVR and RBF were associated with no significant change in renal artery cross-sectional area (0.389 +/- 0.040 to 0.375 +/- 0.033 cm2, p = 0.3). CONCLUSIONS: Stimulation of renal adenosine receptors in patients with CHF results in marked renal vasoconstriction that leads to an important reduction in RBF. Lack of change in renal artery cross-sectional area suggests that adenosine affects intrarenal resistance blood vessels rather than large conductance vessels. These results may indicate a rationale for investigation of renal adenosine receptor blockade for enhancement of RBF and improvement of renal function in patients with chronic CHF.

Adenosine↗
PubMed1998

Calcium channel blockers in heart failure.

A considerable effort has been made in the last 15 years to evaluate the safety and efficacy of calcium channel blockers (CCBs) in the treatment of patients with chronic congestive heart failure (CHF). Available studies have provided strong evidence for a potential detrimental effect of the first-generation calcium antagonists in patients with CHF, indicating the need for great caution when these drugs are used in patients with significant depression of left ventricular systolic function. A number of second-generation CCB have demonstrated a strong vasodilatory effect and favorable hemodynamic action but failed to show a similar improvement in exercise capacity, morbidity and mortality. Moreover, drugs such as nicardipine and nisoldipine have resulted in a detrimental effect in some patients and, therefore, cannot be considered safe when used in patients with moderate-to-severe heart failure. Available information from the V-HeFT III study demonstrate a lack of an unfavorable effect of felodipine on exercise tolerance in patients with chronic heart failure. Although mortality rate was similar in both the felodipine and the placebo group, because of the relatively small number of patients in this study, no clear conclusion can be drawn regarding the effect of felodipine on mortality in patients with CHF. An encouraging signal regarding a potential role of CCB in the treatment of chronic heart failure has been provided by the recently completed PRAISE study. This prospective large-scale study demonstrated the safety of amlodipine, a long-acting dihydropyridine derivative, when used in patients with heart failure due to coronary artery disease. Furthermore, this study demonstrated a substantial reduction in mortality in patients with CHF due to nonischemic cardiomyopathy and provided a strong indication for a potential therapeutic benefit of amlodipine when added to standard CHF therapy in this patient population. No clear explanation is available at the present time regarding the reason for the deleterious effect demonstrated with some of the dihydropyridines and the contrasting benefit seen with amlodipine. Finally, more information regarding the safety and efficacy of dihydropyridines should become available in the next year. The PRAISE II study is ongoing and will provide further information regarding the therapeutic role of amlodipine in patients with nonischemic dilated cardiomyopathy. The MACH-1 study is evaluating the effect of mibefradil, a predominant T-type channel blocker with an ideal activity profile, on morbidity and mortality in patients with chronic CHF.

Calcium Channel Blockers↗
PubMed1997

Incidence of arrhythmias in normal pregnancy and relation to palpitations, dizziness, and syncope.

We assessed the relation between symptoms and cardiac arrhythmias in 110 consecutive pregnant patients without evidence of heart disease referred for evaluation of palpitations, dizziness, and syncope (study group) and in 52 consecutive patients referred for evaluation of an asymptomatic functional precordial murmur (control group). Both groups had a high incidence of arrhythmias on Holter monitoring with atrial premature complexes (APCs) of 56% in the study group and 58% in the control group, > 100 APCs in 7% and 4% of the patients, respectively, and isolated ventricular premature complexes (VPCs) in 59% and 50%, respectively. The number of isolated VPCs was higher and > 50 VPCs/hour were seen in more patients in the study group (3,235 +/- 6,397 vs 678 +/- 3,358 beats/24 hours p < 0.05 and 22% vs 2% p = 0.03). Similarly, the incidence of multifocal VPCs was higher in the study patients (12% vs 2%, p < 0.05). There was no correlation between the incidence of both VPCs or APCs and symptoms, and only 10% of symptomatic episodes were accompanied by the presence of arrhythmias. Repeated Holter monitoring 6 weeks postpartum in 9 women with multiple premature contractions during pregnancy (9,073 +/- 9,210/24 hours) showed a substantial reduction to 1,345 +/- 1,997/24 hours (p < 0.05). Thus, this study confirms an increased incidence of arrhythmias during normal pregnancy. These arrhythmias consist mostly of APCs and VPCs. The number of simple and multifocal VPCs is higher in patients presenting with symptoms of palpitations, dizziness, or syncope; however, there is no correlation between the incidence of arrhythmias and symptoms, and only 10% of symptomatic episodes were accompanied by the presence of arrhythmias.

Adolescent↗
PubMed1997

Comparative effects of losartan and enalapril on exercise capacity and clinical status in patients with heart failure. The Losartan Pilot Exercise Study Investigators.

OBJECTIVES: This study was designed to determine 1) whether 12-week oral administration of losartan, an angiotensin II receptor antagonist, in patients with heart failure is well tolerated; and 2) whether functional capacity and clinical status of patients with heart failure in whom treatment with an angiotensin-converting enzyme (ACE) inhibitor is replaced with losartan for 12 weeks will remain similar to that noted in patients in whom treatment with an ACE inhibitor is continued. BACKGROUND: Losartan is a specific, nonpeptide angiotensin II receptor antagonist. Although specific receptor blockade with losartan has certain theoretic advantages over nonspecific ACE inhibition, definitive demonstration of comparable effects in patients with congestive heart failure is lacking. METHODS: A double-blind, multicenter, randomized, parallel, enalapril-controlled study was conducted in 116 patients with congestive heart failure (New York Heart Association functional classes II to IV) and left ventricular ejection fraction < or = 45% previously treated with stable doses of ACE inhibitors and diuretic agents, with or without concurrent digitalis and other vasodilators. After a baseline exercise period, open-label ACE inhibitors were discontinued, and patients were randomly assigned to 12 weeks of therapy with losartan, 25 mg/day (n = 38); losartan, 50 mg/day (n = 40); or enalapril, 20 mg/day (n = 38). Drug efficacy was evaluated by changes in maximal treadmill exercise time (using a modified Naughton protocol), 6-min walk test, left ventricular ejection fraction and dyspnea-fatigue index. Safety was measured by the incidence of clinical and laboratory adverse experiences. RESULTS: The treadmill exercise time and the 6-min walk test did not change significantly after replacement of ACE inhibitor therapy with losartan. Similarly, a significant change was not observed in either the dyspnea-fatigue index or left ventricular ejection fraction at the end of double-blind period relative to baseline. CONCLUSIONS: Losartan was generally well tolerated and comparable to enalapril in terms of exercise tolerance in this short-term (12-week) study of patients with heart failure. The clinical effects of long-term angiotensin II receptor blockade compared with ACE inhibition remain to be studied.

Activities of Daily Living↗
PubMed1996

Acute myocardial infarction associated with pregnancy.

PURPOSE: To review available information on the epidemiology, cause, diagnosis, prognosis, and treatment of acute myocardial infarction during pregnancy or in the early postpartum period and to develop guidelines for the management of this condition. DATA SOURCES: MEDLINE and Index Medicus searches and a manual search of bibliographies from reviewed articles. STUDY SELECTION: Published reports of well-documented acute myocardial infarction during pregnancy or the early postpartum period or potentially relevant information. DATA EXTRACTION: 125 well-documented cases of myocardial infarction were identified. DATA SYNTHESIS: The highest incidence seems to occur in the third trimester and in multigravidas older than 33 years of age. Acute myocardial infarction during pregnancy is most commonly located in the anterior wall. The maternal death rate was 21%; death occurred most often at the time of acute myocardial infarction or within 2 weeks of the infarction and was usually related to labor and delivery. Most fetal deaths were associated with maternal deaths. Coronary artery morphology was studied in 54% of described patients. Coronary atherosclerosis with or without intracoronary thrombus was found in 43% of patients, coronary thrombus without atherosclerotic disease in 21%, coronary dissection in 16%, and normal coronary arteries in 29%. CONCLUSIONS: Acute myocardial infarction during pregnancy or the early postpartum period is rare but may be associated with high risk. Although atherosclerosis can be documented in many cases, coronary dissection and arteries that are normal on angiography are common, especially in acute myocardial infarction occurring in the peripartum or postpartum period. Early diagnosis is often hindered by the normal changes of pregnancy and low level of suspicion. Management should follow the usual principles of care for acute myocardial infarction. However, selection of diagnostic and therapeutic approaches may be greatly influenced by fetal safety.

Adult↗
PubMed1996

Nitrates in the treatment of congestive heart failure.

Nitrates have been widely used for the treatment of patients with chronic congestive heart failure. Although the use of these drugs has not been evaluated by large-scale studies traditionally used for evaluation of new therapy, multiple studies over the years have demonstrated their favorable effects. Organic nitrates have been shown to have a beneficial effect on ischemia, hemodynamic profile, magnitude of mitral regurgitation, endothelial function, and cardiac remodeling. These drugs alone or in combination with hydralazine have improved exercise capacity, maximal oxygen consumption, cardiac function, and survival. The use of nitrates in patients with heart failure has been limited by reduced responsiveness (resistance) and early development of tolerance. Nitrate resistance is due to reduced vascular response and results in the need to use a larger dose of any nitrate preparation when used for the treatment of patients with heart failure compared to patients without heart failure. Recent information suggests that nitrate tolerance is caused by increased levels of superoxide at the vascular wall, which leads to reduced nitric oxide level and to increased sensitivity to vasoconstrictive mechanisms, such as endothelin and angiotensin II. Intermittent dosing of nitrates allowing a 12-hour nitrate-free interval is effective in preventing nitrate tolerance and is, therefore, recommended. Recent information suggests that augmentation of nitrate dose by the use of an escalating dose regimen and a concomitant use of hydralazine can prevent or overcome the effect of nitrate tolerance in patients with heart failure.

Drug Tolerance↗
PubMed1996

Renal vasodilatory effect of endothelial stimulation in patients with chronic congestive heart failure.

OBJECTIVES: This study sought to examine the vasodilatory response of the renal circulation to endothelial stimulation in patients with chronic heart failure. BACKGROUND: Renal blood flow is often reduced in patients with chronic congestive heart failure and may lead to deterioration of renal function. Stimulation of renal endothelium has been shown to cause renal vasodilation in animals and in isolated human renal artery. The vasoregulatory role of the renal endothelium in patients with heart failure has not been evaluated. METHODS: Renal vasodilatory effect of endothelial stimulation with acetylcholine was assessed and compared with that of endothelial independent vasodilation with nitroglycerin. Both drugs were infused into the main renal artery. Renal artery cross-sectional area was measured with intravascular ultrasound and renal blood flow velocity with the aid of an intravascular Doppler technique. RESULTS: Both drugs caused a significant and comparable increase in renal artery cross-sectional area (maximal increase [mean +/- SE] 14 +/- 5% with acetylcholine, 15 +/- 5% with nitroglycerin; both changes < 0.05 vs. baseline). Acetylcholine also caused a significant reduction in renal vascular resistance (maximal reduction 55+/- 6%) and increase in renal blood flow (maximal increase 136 +/- 54%). In contrast, nitroglycerin administration showed no significant effect on renal vascular resistance and blood flow. CONCLUSIONS: Stimulation of endothelium-derived nitric oxide with acetylcholine results in a significant vasodilatory effect on both conductance and resistance renal blood vessels and leads to a marked reduction in renal vascular resistance and enhancement of renal blood blow. Nitroglycerin, an exogenous nitric oxide donor, caused a selective vasodilatory effect on renal conductance but not on resistance blood vessels and failed to increase renal blood flow. These data suggest the possibility that stimulation of endogenous nitric oxide production in the kidney could be used as a therapeutic target for enhancement of renal flow in patients with heart failure.

Acetylcholine↗
PubMed1996

Prevention of nitrate tolerance with concomitant administration of hydralazine.

Organic nitrates have frequently been used for the treatment of patients with congestive heart failure (CHF). Nitrate tolerance has been identified as a major limitation of this therapy preventing a continuous effect. In the past several years, an effort has been made to develop strategies to prevent nitrate tolerance. Recent animal experimentation has demonstrated the prevention of nitrate tolerance with a concomitant administration of hydralazine. A later study demonstrated similar results in a patient with chronic CHF. The use of oral hydralazine (75 mg qid) resulted in prevention of early development of nitrate tolerance and attenuation of nitrate mediated hemodynamic effects which occurred within the first several hours after initiation of nitroglycerin therapy in the control group not receiving hydralazine. Recent data obtained in in vitro studies have demonstrated enhancement of vascular superoxide production secondary to exposure to nitrates which may be an important mechanism leading to nitrate tolerance. These same studies demonstrated a strong antioxidant effect of hydralazine reducing superoxide formation and preventing nitrate tolerance. Both animal and human experiments have demonstrated prevention of nitrate tolerance with a concomitant use of hydralazine. In vitro studies suggest that hydralazine, by virtue of its antioxidant effect, prevents the nitrate-mediated formation of vascular superoxide, and thus prevents nitrate tolerance. These data provide an explanation for the benefit demonstrated in the V-HeFT studies with the combination of isosorbide dinitrate and hydralazine in the treatment of patients with chronic CHF, and provide a support for the use of this therapeutic regimen in the treatment of patients with chronic heart failure.

Administration, Oral↗
PubMed1995

Cardiovascular problems in pregnant women with the Marfan syndrome.

PURPOSE: To review the available information on the diagnostic, prognostic, and therapeutic aspects of cardiac complications in women with the Marfan syndrome during the peripartum period and to develop guidelines for the approach to these patients on the basis of this information. DATA SOURCES: A MEDLINE search and a manual search of bibliographies from reviewed articles. STUDY SELECTION AND DATA EXTRACTION: Articles that reported on pregnancy in patients with the Marfan syndrome or that discussed potentially relevant aspects of the syndrome. RESULTS: Pregnancy in the Marfan syndrome is associated with two primary problems: potential catastrophic aortic dissection and the risk for having a child with the syndrome. The risk for peripartum aortic dissection is especially high in women in whom aortic root dilatation is diagnosed before pregnancy. Gestation seems to be safer in women without preexisting cardiovascular disease; however, an event-free pregnancy cannot be guaranteed. The Marfan syndrome is inherited in an autosomal dominant manner, and the fetus has a 50% risk for inheriting the mutant gene. CONCLUSIONS: Women with the syndrome should be counseled before conception about the risks of pregnancy to both mother and fetus. Because preconceptual dilatation of the ascending aorta seems to be an important predictor for aortic dissection, it should be excluded before pregnancy. Transesophageal echocardiography seems to be preferable for noninvasive assessment of aortic dilatation before and during pregnancy. Prophylactic use of beta-blockers may be useful in preventing aortic dilatation. Surgery should be considered during gestation in patients with progressive aortic dilatation when or before the aortic root reaches 5.5 cm. Because of the potential risk of ionizing radiation to the fetus, noninvasive methods such as transesophageal echocardiography and magnetic resonance imaging are preferred to contrast aortography for the diagnosis of aortic dissection during pregnancy. Vaginal delivery can be done in patients with the Marfan syndrome who do not have cardiovascular system abnormalities. In patients with aortic dilatation, aortic dissection, or other important cardiac abnormalities, cesarean section should be the preferred method of delivery.

Delivery, Obstetric↗
PubMed1995

Escalating nitrate dose overcomes early attenuation of hemodynamic effect caused by nitrate tolerance in patients with heart failure.

This study was performed to examine the hypothesis that an early attenuation of nitrate effect caused by nitrate tolerance can be overcome by dose increase. We compared hemodynamic effects of constant dose (40 to 120 mg) of oral isosorbide dinitrate (ISDN) given every 6 hours for three doses followed by 12 hours of nitrate washout interval with those of escalating dose (40 mg, 80 mg, and 120 mg) in two similar groups of patients with chronic congestive heart failure. Escalating ISDN dose resulted in a progressive increase in ISDN blood level and overcame early attenuation of effect occurring with a constant dose. At peak effect of the third ISDN dose, a significantly greater reduction was seen in mean right atrial pressure (-59% +/- 27% vs -20% +/- 22%, p < 0.01), mean pulmonary artery pressure (-29% +/- 11% vs -11% +/- 15%, p < 0.01) and mean pulmonary artery wedge pressure (-39% +/- 19% vs -19% +/- 23%, p < 0.05) with the escalating dose. These findings demonstrate that early attenuation of hemodynamic effect caused by nitrate tolerance can be overcome by dose escalation.

Adult↗