Arnold F. Jacobson

Hemodynamic response and change in organ blood volume during spinal anesthesia in elderly men with cardiac disease

Aging and disease may make the elderly patient with cardiac disease particularly susceptible to hypotension during spinal anesthesia.We studied 15 men, 59-80 y old, with histories of prior myocardial infarction (n = 9), congestive heart failure (n = 2), and/or stable myocardial ischemia (n = 11) given spinal anesthesia with 50 mg lidocaine in dextrose. Technetium-99m-labeled red blood cell imaging estimated left ventricular ejection fraction (EF) and changes in blood volume in the abdominal organs and legs. Arterial and pulmonary artery catheters provided hemodynamic measurements. Sensory block averaged T4 (range T1-10). Mean arterial pressure decreased 33% +/- 15% (SD) (P < 0.001), secondary to decreases in vascular resistance (SVR), -26% +/- 13% (P < 0.001) and cardiac output, -10% +/- 16% (P = 0.03). EF increased from 53% +/- 11% to 58% +/- 14% (P < 0.001) while left ventricular end-diastolic volume (LVEDV) decreased (-19% +/- 9%, P < 0.001). Blood volume increased in the legs (6% +/- 6%, P = 0.006), kidneys (10% +/- 9%, P < 0.001), and mesentery (7% +/- 5%, P 0.001) but not in the liver or spleen. Cardiac function was well maintained. We concluded that the primary mechanism of hypotension was a decrease in SVR, not cardiac output, despite the decrease in LVEDV. (Anesth Analg 1997;85:99-105)

Effects of aging on cardiovascular responses to parasympathetic withdrawal

OBJECTIVESnThe study was done to determine whether the effects of parasympathetic withdrawal on heart rate, blood pressure (BP), and systolic and diastolic function are altered with normal aging.nnnBACKGROUNDnCardiac responses to beta-adrenergic sympathetic stimulation decline with aging as does the heart rate response to parasympathetic withdrawal, but the extent to which other responses to parasympathetic withdrawal decrease is less clear.nnnMETHODSnHeart rate, BP, systolic function, and diastolic filling responses to parasympathetic withdrawal induced by atropine (0.02 mg/kg) were compared in 50 healthy subjects, 28 older (ages 65 to 80 years, mean 70 years; 18 females all on estrogen) and 22 young (age 18 to 32 years, mean 26 years; 12 females) subjects, using radionuclide angiography.nnnRESULTSnParasympathetic withdrawal in the older group caused less of an increase in heart rate (+33 vs. +48 beats/min), cardiac index (+0.6 vs. +1.5 l/m(2)), systolic blood pressure (-1 vs. +7 mm Hg), and early diastolic filling rate (+1.7 vs. +2.4 end-diastolic volumes/s) (all p < or = 0.01). At similar declines in the diastolic filling period, end-diastolic volume index (EDVI) fell substantially more in the older group (-11.6 vs. -2.4 ml/m(2), p < 0.001). The only gender difference was in diastolic filling rate, which was similar in the young males and females, but significantly less in older males than in older females.nnnCONCLUSIONSnThe responses to parasympathetic withdrawal as well as sympathetic stimulation decline with aging, and both contribute to the reduced cardiovascular responses to stress with advancing age.

Photopenic defects in marrow-containing skeleton on indium-111 leucocyte scintigraphy: prevalence at sites suspected of osteomyelitis and as an incidental finding

The skeletal distribution of red marrow-containing sites with a decreased uptake of indium-111-labelled leucocytes was examined as part of a retrospective review of 128 consecutive scans in 113 patients. The prevalence of photopenic defects was determined for sites of suspected osteomyelitis and for other skeletal locations included as part of limited or total-body surveys. Of 52 sites suspected of osteomyelitis based upon radiological and clinical data, 21 (40%) demonstrated a decreased leucocyte uptake. The prevalence of photopenia ranged from 79% (11/14) in the spine and 63% (5/8) in the pelvis to 25% (4/16) in the proximal femur and 0% elsewhere in the extremities (0/9) and in the skull (0/3). Fourteen of these 21 defects (67%) were due to active (n=9) or healed (n = 5) osteomyelitis/discitis. All sites of active osteomyelitis showed destructive changes on correlative radiographs and were associated with infectious processes of more than 1 months duration. Thirty-seven photopenic defects were observed as incidental findings. The prevalence of photopenia as an incidental finding ranged from 0% in the skull, neck and chest to 3%–4% in the thoracolumbar spine and pelvis and 14% in the femoral heads, the latter reflecting primarily bilateral loss of femoral head marrow. No incidentally found photopenic defect reflected active osteomyelitis. At sites in the spine and pelvis with radiologic evidence of bone destruction suggetive of osteomyelitis, an absence of normal red marrow uptake of labelled leucocytes often reflects a variant presentation for active chronic infection. In contrast, incidental photopenia is uncommon at all skeletal sites except the femoral heads, and should not raise concern over unsuspected active osteomyelitis.

Indium-111 leukocyte scintigraphic detection of mitral valve vegetations in active bacterial endocarditis

Abstract Echocardiography has been shown to have clinical utility in the diagnosis and monitoring of patients with bacterial endocarditis.1 However, in patients with prosthetic valves or extensive calcification of the leaflets or valve rings, the presence of multiple dense echos may make identification of vegetations or abscess formation difficult.2 Indium-111 leukocyte scintigraphy is capable of identifying areas of abscess formation or active infection,3 but its role in the evaluation and monitoring of patients with endocarditis is not clearly established.4 We report a patient with Staphylococcus aureus endocarditis who had a mitral valve vegetation identified by indium-111 leukocyte scintigraphy.

The effect of aging on phenylephrine response in normal subjects

INTRODUCTION: With aging, cardiac responses to β-adrenergic stimulation decline but the responses to α1-stimulation are less clear. Moreover, whether aging, in the absence of disease, influences the left ventricular response to an increase in afterload is unclear. This study examined the effect of aging on heart rate (HR), blood pressure (BP), cardiac index (CI) and several left ventricular contractility measurements during α 1-stimulation with a phenylephrine infusion. METHODS: Subjects were rigorously screened to be normal by history, physical, blood tests, ECG, ETT and echocardiogram. Twelve young (mean 26 years, all male) and 15 aged (69 years, 11 males) subjects were studied during 10 minute infusions of phenylephrine at 0.5 and 1.0 mcg/ kg/min. HR, BP and radionuclide ventriculographic cardiac volumes were measured. RESULTS: Systolic BP increased more in the aged than in the young (22 vs. 13%, p=0.003), while heart rate (16 vs. 21%, p=0.05) fell less. Contractile responses to phenylephrine, including EF, stroke volume index (SVI), stroke work index and left ventricular contractility index were not altered with aging. Systemic vascular resistance (SVR) was higher at baseline and at each infusion rate, but there was no age-associate change in the response to PE. CONCLUSIONS: In a healthy normal aged population, a preserved SVI response in the setting of a higher baseline SVR results in an increased SBP response to α1-stimulation. Contractile responses to increased afterload are not altered with aging. Age-associated differences in the response to α1-stimulation are small and are explained by altered baroreflex sensitivity and a stiffer vasculature.

Beta blocker dose and markers of sympathetic activation in heart failure patients: interrelationships and prognostic significance

Extent of cardiac sympathetic activation can be estimated from physiological parameters, blood biomarkers, and imaging findings. This study examined the prognostic value of three markers of sympathetic activity and their relationship to beta blocker dose in heart failure patients.

Persistence of 123I-mIBG Prognostic Capability in Relation to Medical Therapy in Heart Failure (from the ADMIRE-HF Trial)

123I-mIBG imaging has been evaluated to assess sympathetic function and prognosis in heart failure (HF). However, the effect of combined HF medical therapies on 123I-mIBG uptake and its prognostic significance has not been previously examined. This analysis examined the relation between the intensity of guideline-directed HF medical therapy and global 123I-mIBG cardiac uptake in the AdreView Myocardial Imaging for Risk Evaluation in Heart Failure (ADMIRE-HF) database. A second objective was to investigate whether this guideline-based therapy, measured by total medication doses, had the expected effect on outcome, that is, that patients with higher 123I-mIBG cardiac uptake and more intensive medical therapy had the fewest outcome events. Three HF cardiologists developed an HF Medication Score (HFMS) to quantify adequacy of dosages of β blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers and mineralocorticoid receptor antagonists. A Cox model was used to investigate the predictive ability of the HFMS for mortality events during median 17xa0months follow-up. Multiple regression and Cox models assessed the usefulness of the HFMS relative to the planar heart/mediastinum ratio (H/Mp) from 123I-mIBG imaging in prediction of an event and to characterize the interaction of HFMS and H/M in predicting an event. HFMS was not a significant predictor of all-cause or cardiac death in either univariate or multivariate Cox models; H/Mp was highly significant for both event categories (p <0.0001). Mean H/Mp did not differ among HFMS ranges 0 to 3, 4 to 6, and 7 to 9. However, within each category, the mean H/Mp for subjects with events was significantly lower than that of subjects without events, with the exception of cardiac mortality in those with highest scores. In conclusion, intensity of medical therapy is not predictive of short-term mortality in HF patients. H/Mp is a good predictor for both cardiac and overall mortality regardless of medical therapy levels.

Renin-Dependent Renal Parenchymatous Hypertension Detected by Angiotensin-Converting Enzyme Inhibitor Renography

Hypertension secondary to an activated renin-angiotensin system without renal artery stenosis can be detected by angiotensin-converting enzyme (ACE) inhibitor renography. Two cases of renin-mediated hypertension without major or branch vessel stenosis supplying the kidney with parenchymatous disease were discovered by ACE inhibitor renography.