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Biomedical subjects

H O Ventura

Publications and source records attributed to H O Ventura.

At least 19 recordsLinked to original sources
PubMed2004

Ventricular-vascular uncoupling increases expression of B-type natriuretic peptide in heart transplantation.

BACKGROUND: Allograft adaptation to a foreign circulation is imperfect as noted from persistent limitations to stress. Effective arterial elastance (Ea), a measure of afterload, provides an estimate of aortic impedance. End systolic elastance (Ees) is a load-independent measure of ventricular performance as well as its interaction in the periphery. The ratio (Ea to Ees) characterizes ventricular-vascular coupling; a value close to unity signifies poor mechanical efficiency. The purpose of this investigation was to correlate mechanical efficiency of work with expression of B-type natriuretic peptide BNP, a specific marker of ventricular stress and strain. METHODS: We measured BNP levels in 40 consecutive stable heart transplant recipients free from rejection. In addition, echocardiography was performed to obtain Ea, Ees, and their ratio (Ea to Ees) by the single-beat method. We examined correlates of BNP expression by assessing Ea to Ees, while correcting for mean arterial pressure, body mass index, left ventricular mass index, ejection fraction, and serum creatinine. RESULTS: BNP levels were significantly and positively correlated (r=0.38, P=.05) with an increased Ea to Ees ratio. By multivariable analysis, this relationship persisted independently (t=2.1, P=.04), while the five other measures were insignificant predictors. CONCLUSION: This investigation indicated that the transplanted heart demonstrates poor contractile efficiency and operates at maximal left ventricular work. This is paralleled by a tandem increase in BNP, suggesting that elevation in this stress peptide is at least partly explained by ventriculo-vascular uncoupling in heart transplantation, independent of alterations in blood pressure.

Coronary Circulation↗
PubMed2004

Corticosteroid weaning in the tacrolimus and mycophenolate era in heart transplantation: clinical and neurohormonal benefits.

BACKGROUND: Compared with cyclosporine, tacrolimus-based immunosuppression yields improved metabolic outcomes in heart transplantation. Whether corticosteroid freedom provides incremental metabolic benefits in tacrolimus and mycophenolate mofetil immunoprophylaxis remains uncertain. METHODS: In a prospective trial, 41 heart transplant patients treated with tacrolimus and mycophenolate mofetil underwent steroid weaning immediately after transplantation until weaning was complete. Weaning was interrupted only for treated rejection with or without hemodynamic compromise. Benefits of steroid weaning assessed following the first year included B-type natriuretic peptide (BNP), late infections, lipids, blood pressure, hyperglycemia, and body mass index (BMI). RESULTS: Of this 41 patient cohort (age 53 +/- 9 years, 50% black American, 35% women) followed for a total of 47 +/- 5 months, 25 had corticosteroids discontinued (62%) by an average of 20 +/- 11 months. No differences between the two groups were noted in baseline characteristics. Significant predictors of failure to wean steroids included higher rejection, BNP, and lower dose of mycophenolate mofetil. No significant benefits of steroid weaning were noted on lipids, blood pressure, hyperglycemia, and BMI. However, late infections (after 1 year) requiring hospitalizations were more frequent in the failure to wean group (0.60.4 vs 0 infections/patient/y, P <.001). INFERENCES: Unlike known metabolic benefits of steroid withdrawal with cyclosporine, heart transplant recipients treated with tacrolimus and mycophenolate mofetil demonstrate no incremental metabolic benefits, but instead experience benefits of decreased serious late infections. Furthermore, failure to discontinue corticosteroids in this series is predicted by early allograft rejection, use of lower doses of mycophenolate mofetil, and higher BNP levels suggesting poor cardiac adaptation.

Adrenal Cortex Hormones↗
PubMed2001

Treatment of heart failure according to William Stokes: the enchanted mercury.

BACKGROUND: It was not until 1919 that the diuretic properties of mercury were observed in patients with syphilis; in the same year the beneficial effects of mercurial diuretics were shown in a patient with severe rheumatic heart disease and anasarca. However, mercury had been used much earlier for the treatment of dropsy without clear guidelines. In this article we describe William Stokes' insights into the treatment of heart failure, focusing on the beneficial diuretic properties of mercury. METHODS: We reviewed the chapter "Treatment of the Weak and Probably Dilated Heart in Connexion With Enlargement of the Liver and Pulmonary Disease" in William Stokes' famous treatise The Diseases of the Heart and the Aorta. CONCLUSIONS: Stokes makes several important clinical observations. First, he provides precise guidelines on when and how to use mercury in these patients. Second, he realizes the importance of mercury for the treatment of decompensated heart failure. Stokes recognizes the cyclical nature of frequent decompensation in congestive heart failure, the relationship of clinical deterioration and reduced urine output, and the importance of reestablishing urinary flow to ameliorate dyspnea. Third, he attempts to define the mechanism of action "... if any of the characteristic action of mercury can be perceived unless we include diuresis." Finally, he gives interesting guidelines on the dosage and side effects of mercury. These observations on the treatment of "congestive" heart failure are an important contribution to the understanding of heart failure pathophysiology and the design of prescription regimens for this disease.

Heart Failure↗
PubMed2001

Desperate diseases, desperate measures: tackling malignant hypertension in the 1950s.

BACKGROUND: The conquest of malignant hypertension is one of the most important medical achievements of the second half of the 20th century. As we enter the new millennium, it is critical to examine the efforts that have led to our ability to treat this once incurable disease. METHODS: Review was performed of the literature from 1900 to the 1950s regarding the etiology, clinical evaluation, and treatment of hypertension, focusing on malignant hypertension. RESULTS: Fifty years ago, in a time of sparse treatment options, the occurrence of malignant hypertension was a dreaded event that taxed the aptitude of the clinician. Confronted with an "extreme disease," physicians chose to use "extreme methods of cure" in conformity with the teaching of Hippocrates. In the 1950s malignant hypertension was treated with such drastic measures as rice diet, sympathectomy, and intravenous pyrogens. CONCLUSIONS: In the practice of medicine today, while work is being done to reassert biomolecular mechanisms, we still face patients who have reached the end stages of failure and manifest devastating morbidity. These patients are subjected to "extreme therapies" reminiscent of those that surrounded malignant hypertension in the past. In an era when adequate treatment of hypertension has become a reality for so many patients, it is appropriate to give credit to those who paved the way to such great progress.

Antihypertensive Agents↗
PubMed2001

Historical perspectives on cardiac transplantation: the past as prologue to challenges for the 21st century.

The development of cardiac transplantation is based on experimental studies that started in the beginning of the last century. The improvement in the surgical technique for cardiac transplantation, associated with other progress in the field of cardiac surgery and a better understanding of the immune responses, allowed cardiac transplantation to become a reality for the treatment of endstage heart disease. Recent development in immunosuppressive agents and advances in cardiac surgery have meant that cardiac transplantation is not a "fantastic speculation for the future," but a reality for the present. Thus, cardiac transplantation is performed around the world with an excellent survival rate and has become a lifesaving treatment for many patients with severe heart disease.

Animals↗
PubMed2000

Study of arterial and autonomic effects of cyclosporine in humans.

Altered sympathetic activity and peripheral vascular function are suspected as a mechanism of the development of arterial hypertension in organ transplantation recipients treated with cyclosporine. We assessed whether cyclosporine might alter peripheral vascular properties or autonomic modulation of the sinus node and the vasculature during rest and standing. We examined 17 orthotopic heart transplantation recipients, 8 solid organ transplantation recipients, 17 patients with essential hypertension, and 42 normotensive control subjects. All except the normotensive control subjects were treated with a long-acting dihydropyridine calcium entry blocker; transplantation recipients also received cyclosporine-based immunosuppression. Radial artery compliance was reduced in patients with essential hypertension and in patients with heart and solid organ transplantation as compared with normotensive control subjects, with this reduction being more marked in heart transplantation recipients. At rest, R-R variance was lowest in heart transplantation recipients, denoting denervation. The spectral profile of both R-R and systolic blood pressure variability as well as the index of baroreflex gain was normal at rest in patients with solid organ transplantation. On standing, both transplantation groups demonstrated reduced responsiveness in markers of autonomic modulation. The decrease in arterial compliance in cyclosporine-induced hypertension seems to imply a degree of ventricular vascular uncoupling more apparent in heart transplantation recipients. These changes are associated with alterations in autonomic modulation that are evidenced by an orthostatic stimulus.

Adult↗
PubMed1999

The prognostic implications of outpatient diuretic dose in heart failure.

In 111 patients with left ventricular ejection fraction < or =30% who required hospitalization for heart failure, we examined the association between outpatient dose of diuretic agents and all-cause mortality. In comparison to patients who were not on treatment with diuretics prior to hospitalization, patients being treated with 'low' doses of diuretics (<80 mg/day of furosemide) and those being treated with 'high' doses of diuretics (> or =80 mg/day of furosemide) were more likely to die during follow-up after adjustment for other clinical parameters (adjusted relative risks, RR, 3.1 and 4.6).

Aged↗
PubMed1999

The independent effects of left ventricular ejection fraction on short-term outcomes and resource utilization following hospitalization for heart failure.

BACKGROUND: While depressed left ventricular ejection fraction is clearly associated with poor long-term outcome in heart failure (HF), the effect of ejection fraction on short-term outcomes and resource utilization following hospitalization for HF remains unclear. HYPOTHESIS: We evaluated the independent effect of depressed ejection fraction (< or = 40%) on short-term outcomes and resource utilization following hospitalization for HF. METHODS: The study population included 443 consecutive patients hospitalized for DRG 127 (HF and shock) with known ejection fraction. For each patient, we assessed the hospitalization cost (1995 US$), length of stay, in-hospital mortality, 30-day mortality, and 30-day readmission rates. RESULTS: Despite similar disease severity at admission, patients with ejection fraction < or = 40% (Group 1) had longer length of stay (4.0 vs. 3.7 days; p = 0.03), a tendency toward higher hospitalization cost ($3,054 vs. $2,770; p = 0.08), more readmissions for any cause (0.4 vs. 0.3; p = 0.05) and for HF (0.2 vs. 0.1; p = 0.01), but similar in-hospital (2.5 vs. 2.6%) and 30-day mortality (4.0 vs. 4.6%) compared with patients with ejection fraction > 40% (Group 2). In multivariate analyses, Group 1 patients were more likely to have higher than median hospitalization cost [odds ratio (OR) = 1.98; 95% confidence intervals (CI) = 1.02-3.91] and longer than median hospital stay (OR = 1.68; CI = 1.08-3.91); they were also more likely to be readmitted for any cause (OR = 2.07; CI = 1.15-3.78) or for HF (OR = 5.71; CI = 1.64-21.94), and they tended to have a higher 30-day incidence of death or readmission (OR = 1.65; CI = 0.96-2.84). CONCLUSIONS: Depressed left ventricular ejection fraction is associated with higher resource utilization and readmission rates following hospitalization for HF. Greater focus on patients with depressed ejection fraction may increase cost savings from HF disease management programs.

Aged↗
PubMed1998

Coronary stenting in cardiac allograft vasculopathy.

OBJECTIVE: The purpose of this study was to evaluate acute angiographic success, in-hospital complications and long-term outcome after intracoronary stenting in patients with cardiac allograft vasculopathy. BACKGROUND: The application of conventional interventional modalities to treat discrete lesions in patients with cardiac allograft vasculopathy is associated with higher procedural morbidity, mortality and higher restenosis compared to atherosclerotic coronary artery disease. Elective coronary stenting has been shown to lower restenosis rates and improve long-term outcome in selected patients with native coronary artery disease; however, its safety and efficacy in reducing restenosis in patients with cardiac allograft vasculopathy is unknown. METHODS: Ten patients with 19 discrete lesions in a major coronary artery without diffuse distal disease underwent intracoronary stenting using Palmaz-Schatz stents. The average stent size was 3.4 mm, and the stent/artery ratio was 0.99+/-0.07. Eight of ten (80%) patients received antiplatelet therapy (aspirin plus ticlopidine) only. RESULTS: Procedural success was 100% with no in-hospital stent thrombosis, Q-wave myocardial infarction or death. Minimal luminal diameter increased from 0.83+/-0.38 mm to 3.23+/-0.49 mm after stenting. Diameter stenosis decreased from 74.91+/-11.52% to 5.90+/-4.09% after stenting. Follow-up angiography was performed in 8 of 10 (80%) patients and 16 of 19 (84%) lesions. Target lesion revascularization was required in 2 of 10 (20%) patients and 3 of 16 (19%) lesions. Allograft survival was 7 of 10 (70%) at the end of 22+/-11 months follow-up. CONCLUSIONS: Intracoronary stenting can be performed safely with excellent angiographic success in selected patients with cardiac allograft vasculopathy. The restenosis rate appears to be low despite the aggressive nature of the disease. A multicenter study with a larger number of patients is required to assess its efficacy in reducing restenosis and improving allograft survival.

Coronary Angiography↗
PubMed1998

Effects of caregiver specialty on cost and clinical outcomes following hospitalization for heart failure.

In 614 consecutive hospitalizations with the primary discharge diagnosis of diagnosis-related group (DRG) 127 (heart failure and shock), we sought to assess the effect of caregiver specialty (generalist, n = 217; cardiologist, n = 397) on hospital costs, length of stay, and in-hospital mortality. Patients treated by cardiologists were younger (68 vs 71 years) and less likely to have hypertension (52% vs 61%), but were more likely to be men (61% vs 44%), require an intensive care stay (13% vs 5%), have coronary artery disease (49% vs 23%), have a left ventricular ejection fraction <40% (74% vs 49%), and have lower systolic (132 vs 146 mm Hg) and diastolic (76 vs 81 mm Hg) blood pressures on admission. Predictors of acute disease severity were similarly distributed between the 2 groups. No difference was found between patients treated by cardiologists versus those treated by generalists with respect to crude or adjusted hospital cost, length of stay, and in-hospital mortality. However, in subsets of patients who required intensive care during hospitalization (n = 64), as well as those who did not (n = 550), care by cardiologists was associated with a lower adjusted hospital cost. Any potential cost savings that could have accrued from care by cardiologists was, however, negated by the higher proportion of patients treated by cardiologists who required intensive care during hospitalization. We conclude that when differences in clinical variables are adjusted, care by cardiologists versus generalists is associated with similar or lower hospital cost for patients with DRG 127. Our findings challenge the notion that in-patient care provided by specialists is more expensive than that provided by generalists.

Adult↗
PubMed1998

Colles-Stokes contributions to the concept of heart failure.

"Colles fracture," "Colles law," "Stokes-Adams syndrome," "Cheyne-Stokes respiration," and "Corrigan pulse" are some of the contributions of the Irish school that are utilized for teaching purposes in medical schools and training programs, as well as in daily practice of medicine. We wish to add an important description by Drs. Colles and Stokes that personifies the considerable personal contributions of these 2 physicians in our understanding of the pathophysiologic expression of the syndrome of heart failure. The clinical-pathologic correlation of the disease that affected Dr. Colles is well described by Dr. Stokes in his treatise Diseases of the Heart and the Aorta. He recognized the cyclical nature of frequent decompensations in heart failure, the relation of clinical worsening in conjunction with reduced urine output, as well as the importance of reestablishing urinary flow to achieve a decrease in dyspnea. Dr. Colles also demonstrated a profound clinical insight when he noticed, first, that his affliction was "eventually a fatal disease and that remedies that work may lose effect over time," illustrating an observation that has stood the test of time and, secondly, when he told Dr. Smith "... I would direct particular attention to the heart and the lungs ... and the swelling in the right hypochondrium ... I suspect that there is some connexion between this swelling of the hypochondrium and the diseased state of the heart." We believe that the Colles-Stokes contributions, both in the clinical as well as the clinical-pathologic arenas, are one of the landmark descriptions that helped to evolve the concept of the syndrome of heart failure.

Cheyne-Stokes Respiration↗
PubMed1998

Mitral inflow and pulmonary venous Doppler measurements do not predict pulmonary capillary wedge pressure in heart transplant recipients.

BACKGROUND: Noninvasive estimation of pulmonary capillary wedge pressure (PCWP) with Doppler-derived mitral inflow pattern has been shown to correlate well with invasively measured PCWP; however, it has not yet been determined whether Doppler-derived mitral inflow pattern can be used to estimate PCWP accurately in heart transplant recipients. METHODS: To determine if mitral and pulmonary venous inflow data can be applied to calculate PCWP in heart transplant recipients, some-day echocardiograms and right heart catheterizations were reviewed and 83 echocardiograms with adequate mitral inflow patterns in 53 patients were studied. Twenty-eight studies that also had adequate pulmonary venous inflow patterns were selected for offline analysis. RESULTS: Using a previously published formula [PCWP = 17 + (5.3 x E/A) - (0.11 x IVRT)], where E/A is the ratio of early to late mitral inflow velocities and IVRT is the isovolumic relaxation time, we derived a calculated PCWP, the results of which compared poorly with the measured PCWP (r = 0.33; p = 0.002). Linear regression analysis of measured PCWP versus mitral inflow Doppler flow velocity parameters also revealed poor to modest correlation. Adding parameters derived from the pulmonary venous inflow patterns failed to improve this correlation. CONCLUSION: Doppler-derived estimation of PCWP with mitral and pulmonary venous inflow patterns cannot be used to reliably predict PCWP in heart transplant recipients.

Adolescent↗