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Over the past 15 years, the primary goal of our physiology laboratory has been to improve the understanding of basic myocardial function in both normal and diseased hearts. Very early in our studies, it became evident that existing descriptors of myocardial performance were deficient, and initial efforts were expended to develop basic models of ventricular geometry, diastolic properties, and systolic function. Later work has been directed toward applying these models to the study of pathophysiology in ischemic heart disease and chronic volume overload. Although this investigation is still in progress, enough information is currently available to provide insight into basic aspects of diastolic myocardial function, to propose several hypotheses on how the heart adapts to clinical heart disease, and to provide direction for future clinical investigation of myocardial mechanics in humans. This chapter will review these topics primarily through publications from our laboratory, each of which contains full references.

This study was designed to more clearly define the relation between various invasive hemodynamic measurements and left ventricular (LV) timing intervals, ejection rate and filling rate derived from the radionuclide angiographic volume curve. Twenty-eight patients were studied with simultaneous intracardiac micromanometer pressure and dP/dt recordings, gated radionuclide angiography and M-mode echocardiography. These techniques permitted multiple variables of systolic and diastolic function to be measured at a constant atrial paced rate of 100 beats/min. There was a strong correlation between peak ejection rate and ejection fraction (r = -0.97) and between peak ejection rate and maximum positive dP/dt (r = -0.85). There also was a strong correlation between peak filling rate and maximum negative dP/dt (r = -0.85). A weaker correlation existed between the time constant of LV relaxation and the peak filling rate (r = -0.49) and between the LV end-diastolic pressure and the peak filling rate (r = -0.62). There was no correlation between the modulus of chamber stiffness and filling rates, and no association was observed between the time to peak filling rate and the hemodynamic variables. Thus, under the conditions studied, the measured peak ejection and filling rate, determined from the radionuclide angiographic volume curve, correlated well with accepted invasive hemodynamic measurements.

The effects of intermittent infusions of dobutamine were studied in young normal male subjects during a period of bedrest deconditioning to determine whether this synthetic catechol affects physical conditioning processes in humans. 24 volunteers were placed at bedrest and randomized to daily 2-h treatments of saline infusions (control), dobutamine infusions, or maintenance exercise (control). Exercise, hemodynamic, and metabolic studies were performed at base line and at the termination of the 3-wk treatment period. Maximal exercise (duration, oxygen consumption, and workload) fell for the saline group and remained unchanged for the dobutamine and exercise groups. Hemodynamics during exercise were maintained the same as pretreatment base line for the dobutamine and exercise groups, whereas stroke volume and cardiac output dropped and heart rate rose for the saline group. The metabolic profile showed an increased blood lactate response at rest and during submaximal exercise after 3 wk of bedrest for the saline group, and essentially no change for the exercise and the dobutamine groups. Extraction of oxygen across the exercising lower limb rose for the dobutamine group, as did the activity of the skeletal muscle oxidative enzymes, citrate synthetase, and succinate dehydrogenase. In contrast to the exercise control group, the saline and dobutamine groups developed orthostatic hypotension, tachycardia, and accentuation of the renin-aldosterone response over the 3-wk treatment period; for the saline group, this is best explained by the observed fall in blood volume and for the dobutamine group, by the blunting of vascular vasoconstrictive responses. During a period of bedrest deconditioning in humans, infusions of dobutamine maintain many of the physiologic expressions of physical conditioning.

The effect of intracoronary papaverine administration on epicardial coronary arterial diameter was examined in 18 male patients. Coronary-artery cineangiograms were acquired with a power injector before intervention, 20 sec after intracoronary saline (control), and 20 sec after administration of papaverine into either the left (12 mg) or right (8 mg) coronary artery. Absolute coronary arterial diameter of a normal-appearing segment was quantified using a previously validated, fully automated digital edge detection program with an ADAC digital radiographic unit. Baseline coronary arterial diameter of 3.1 +/- 0.8 mm did not significantly change after saline administration (3.1 +/- 0.9 mm) but did significantly increase (p less than .001) to 3.4 +/- 0.9 mm after papaverine administration. No significant percent change in diameter occurred in either the left anterior descending (-.5 +/- 1.7%), left circumflex (-.2 +/- 1.1%), or right (-3.0 +/- 3.8%) coronary arteries with saline, but significant (p less than .001) increases occurred with papaverine (7.2 +/- 4.1%, 7.0 +/- 4.5%, 6.8 +/- 2.7%, respectively). The response of 7 coronary arteries examined immediately proximal to a significant lesion was not significantly different from the response of the remaining 11 coronary arteries. In conclusion, intracoronary papaverine causes a significant increase in coronary arterial diameter. This has clinical implications for assessing coronary flow reserve with devices that defect flow velocity.

Study objective To prospectively investigate the evidence for embolic phenomena associated with percutaneous mitral and aortic valvuloplasty. Design Prospective, consecutive case series before and after balloon valvuloplasty. Setting Referral center hospital and cardiac catheterization laboratory. Patients Consecutive sample of 32 patients having balloon valvuloplasty for critical symptomatic stenosis of the mitral or aortic valve. Twenty-six patients had aortic stenosis; 6 had mitral stenosis. Intervention Computed tomography of the head, funduscopy, and electrocardiography were done in all patients before and after valvuloplasty. Cardiac isoenzymes were measured serially in 19 patients. Measurements and main results Previous cerebral infarction was seen in nine patients, with three showing a new abnormality after aortic valvuloplasty. In one of these patients a funduscopic hemorrhage was detected by photography. Total creatinine kinase and MB fraction were elevated in 1 of 19 patients. Serial electrocardiograms were unchanged in all patients. Conclusions The incidence of cerebral neurologic events and myocardial injury are acceptably low after balloon valvuloplasty of calcific aortic and mitral stenosis. Both episodes of symptomatic cerebral infarction occurred in patients with apparent bicuspid aortic valvular stenosis, suggesting that calcific bicuspid aortic stenosis may be associated with more neurologic events after aortic valvuloplasty.

The dynamics of the delayed accentuated mitral component (M 1 ) of the first heart sound and the MOS were studied in 11 patients with mitral stenosis of varying severity. Echophonocardiographic (M-mode and 2D) studies were performed with analysis of LA dimensions, dynamics, and mitral valve excursion at the time of M 1 and MOS. LA area and length, mitral annular diameter, and mitral dome area (from anulus plane to fused valve tip) and length were measured at M 1 and MOS. Significant dynamic increases in mitral dome area and length occurred from M 1 to MOS, with less striking but consistent increases in LA area, LA length, and mitral annular diameter. Conversely, mitral dome area and length decreased significantly from MOS to M 1 , with less striking but consistent decreases in LA area, LA length, and mitral annular diameter. Frame-by-frame video tape analysis showed that dome movement was separate from anulus motion. Mitral dome descent into the left ventricle terminated at MOS and reversal of dome motion terminated at M 1 . The conformational and dimensional changes that terminated abruptly at MOS reversed and terminated abruptly in a reciprocal manner at the time of the delayed, accentuated M 1 . When considered in light of known hemodynamic, pressure pulse, and imaging correlates in mitral stenosis, these observations strengthen the hypothesis that the mechanisms involved in the production of M 1 and MOS in mitral stenosis are paired or reciprocal in nature, and the delayed, accentuated M 1 and the MOS of mitral stenosis are reciprocal cardiovascular sounds.

To investigate the safety and efficacy of inferior vena caval (IVC) balloon occlusion for preload alteration in humans, 13 patients with dilated cardiomyopathy were studied before and during repeated (total of 78) IVC occlusions. Left and right ventricular (LV and RV) micromanometer pressures were simultaneously measured and M-mode and 2-D echocardiograms were recorded at end expiration. Complications were limited to abdominal discomfort in 2 patients. With IVC occlusion, RV collapse fluoroscopically shifted the heart toward midline and ventricular septal motion was frequently disordered. Significant (p = 0.001) changes occurred in RV and LV systolic peak pressures (from 19 +/- 6 to 12 +/- 5 mm Hg and from 129 +/- 34 to 109 +/- 25 mm Hg, respectively). LV and RV end-diastolic pressures also decreased significantly (from 18 +/- 7 to 6 +/- 6 mm Hg and from 5 +/- 3 to 2 +/- 2 mm Hg, respectively) (both p less than or equal to 0.0055). Similarly, LV end-diastolic diameter decreased 13% (from 61 +/- 11 to 53 +/- 12 mm, p = 0.0002). Mean heart rate did not change significantly (from 76 +/- 19 to 78 +/- 21 beats/min). Thus, IVC balloon occlusion provides a safe method of repeatedly altering loading conditions in humans. This approach allows for acquisition of important information regarding cardiac chamber dynamics while minimizing the effects of reflex mechanisms and avoiding use of pharmacologic agents.

We evaluated a patient who had transient episodes of hypotension with clinical and laboratory features apparently distinct from previously recognized disorders of vasomotor regulation. In between his abrupt attacks of hypotension, the patient is asymptomatic and demonstrates normal autonomic modulation of heart rate and blood pressure in response to changes in body position, Valsalva maneuver, cold, and exercise. During periods of hypotension, his plasma norepinephrine falls markedly and he has blunted or absent responses to stimuli that normally have a pressor effect due to sympathetic efferent discharge. Mechanical or known hormonal disorders that produce episodic hypotension have been excluded by extensive testing. We suggest two possible causes for our patient's paroxysmal sympathetic withdrawal: first, a centrally mediated inhibition of sympathetic discharge to peripheral resistance and capacitance vessels, but with no afferent stimulus reflexly producing sympathetic withdrawal readily evident; or second, an episodic release of an unknown endogenous compound with inhibitory effects upon central or preganglionic sympathetic neurons or upon postganglionic sympathetic neurons by a presynaptic inhibition of norepinephrine release.

Cardiac disease is the most important cause of non-obstetrical maternal death. 1 Atrial septal defect (ASD), which has a 2:1 female predominance, is the most common congenital heart disease during pregnancy. 1 Echocardiographically guided cardiac catheterization may be an option in patients in whom definitive hemodynamic data are needed for decision making. 224

A case of right ventricular aneurysm due to coronary artery disease in a 69-year-old male with no prior history of surgery or chest trauma is reported. The presence of the aneurysm was diagnosed by gated radionuclide angiography and confirmed by contrast angiography. This is the first description of an isolated right ventricular aneurysm on the basis of ischemic disease. In addition, the patient had recurrent ventricular tachycardia and frequent premature ventricular contractions (PVC's). Using radionuclide angiographic phase analysis of the PVC's, their apparent origin was localized to the margin of the right ventricular aneurysm.

To examine the effects of digital image acquisition mode and subtraction techniques on the results of coronary stenosis quantitation, 100 discrete lesions from 45 patients undergoing routine diagnostic angiography were analyzed in each of 3 image types: direct on-line digital, electrocardiogram-gated digital subtraction and digitized cine film images. For the geometric measurements (minimal lumen diameter and percent diameter stenosis) correlation coefficients for 2-way comparisons among the image types ranged from 0.90 to 0.96. Linear regression slopes ranged from 0.93 to 1.00, with intercepts from 0.03 to 0.07 mm for minimal diameter and −0.5 to 4.4% for percent diameter stenosis. For the videodensitometric percent area stenosis data, the correlation coefficients ranged from 0.80 to 0.89, with linear regression slopes from 0.84 to 0.89 and intercepts from 8.3 to 12.8%. Thus, the results of quantitative geometric measurements of coronary stenosis severity were not strongly affected by image acquisition mode (on-line versus cine film digitization) or by electrocardiogram-gated digital subtraction, while densitometric data correlated less well when on-line digital and digitized cine film acquisition methodology were compared.

Eighteen patients with isolated left bundle branch block (LBBB) were compared with 10 normal control subjects. Apexcardiograms, phonocardiograms, electrocardiograms, two-dimensional and dual M-mode echocardiograms, and radionuclide ventriculograms (RNV) were performed. There were no differences in the timing of right ventricular events between LBBB and normal subjects; however, striking delays in left ventricular systolic and diastolic events were apparent in the LBBB group. The delay was associated with shortening of left ventricular diastole and resultant increase in the ratio of right to left ventricular diastolic time in LBBB (1.2 +/- 0.08) compared with normal (1.0 +/- 0.06), p less than 0.0001. First heart sound (S1) amplitude, expressed as the ratio S1/S2, was decreased in LBBB compared with normal (0.67 +/- 0.2 compared with 1.34 +/- 0.25, p less than 0.01), in part due to wide separation of the valvular contributors to S1. The abnormal interventricular septal motion in LBBB corresponded to periods of asynchrony in contraction, ejection, end systole, and end diastole between right and left ventricles. Radionuclide ventriculograms revealed decreased regional ejection fraction of the septum in LBBB (40 +/- 16%) compared with 67 +/- 7% in normal subjects (p less than 0.001), while the apical and lateral regional ejection fractions were similar in the two groups. This loss of septal contribution resulted in a reduction in global ejection fraction in LBBB compared to normals (54 +/- 7% compared with 62 +/- 5%, p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Ventricular filling rates derived from radionuclide angiographic (RNA) time-activity curves are commonly expressed as normalized values. The assumption that normalized filling rates have a relationship to the actual filling rates was tested. RNA and contrast angiography were performed within 20 min of one another in 21 patients with widely disparate volumes. The RNA time-activity curve was converted from counts to milliliters by equating the contrast angiography derived end diastolic volume to the end diastolic count rate determined by RNA. Peak filling rates were normalized to end diastolic volume (EDV), stroke volume (SV, and peak ejection rate (ER). No significant correlation between the normalized filling rates and the true filling rate was found. Significant correlations were found between the EDV normalized filling rate and the EDV (r = -0.70) and the ejection fraction (r = 0.89). Normalized filling rates are dependent upon the normalizing variable and are not a pure measure of ventricular filling rates. As the technique of gated radionuclide angiography has matured, it has become apparent that there is more information in the time-activity curve than just the ejection fraction. The emptying rates, filling rates, time to peak emptying, and time to peak filling are parameters that are also available from the time-activity curve. Several authors have used this information to quantitate ventricular ejection and filling rates [1-6]. Since the contrast angiography literature would indicate that in some disease states ventricular filling is impaired [7,8], attempts have been made to identify impaired filling rates by radionuclide techniques. Using this method, decreased normalized filling rates have been found in groups of patients with coronary artery disease and it has been suggested that the observed decrease is due to impairment of active relaxation and/or to reduced compliance [2,3,5,6]. It has even been suggested that the decrease seen in the normalized filling rates may be a reflection of ischemia in the resting patient [6]. While these RNA derived parameters have been normalized to end diastolic volume by most authors, normalization to stroke volume and maximum ejection rate have also been suggested [9,10]. A possible rationale for normalization is that the activity measured over the ventricle is dependent upon many factors, including radionuclide dose, attenuation from the patient's chest wall, the specific type of collimator used, thickness of the crystal, and the window width.(ABSTRACT TRUNCATED AT 400 WORDS)

It has been suggested that the effect of a premature ventricular contraction (PVC) on left ventricular (LV) function depends on the site of origin of the PVC, and that the subsequent impairment of LV performance during a PVC may be more pronounced if baseline LV dysfunction is present. To evaluate these concepts, radionuclide angiographic phase image analysis of spontaneous PVCs was performed after acquisition of images from PVCs alone by a new gating procedure. The sites of the PVCs were localized to 1 of 3 right ventricular (RV) or 5 left ventricular (LV) regions by this method. LV function during PVCs was assessed and compared with baseline by noting the LV ejection fraction (EF) during PVCs, the difference between sinus LVEF and PVC EF, and the normalized PVC EF (PVC EF/sinus EF). Twenty-four patients had LV PVC sites and 19 had RV sites. LV function during a PVC appeared to be independent of either the ventricle of origin of the PVC or a specific site of origin within the ventricles. The resultant PVC ventricular function also appeared independent of sinus LVEF and sinus wall motion abnormalities. In addition, no correlation between coupling interval and any of the variables measured was demonstrated (although extremely short coupling intervals were not evaluated). These data suggest that the effects of PVCs on ventricular performance seen during ventricular ectopy are independent of the site of origin of the PVC, baseline wall motion abnormalities or PVC coupling interval in the population studied.

The high-energy myocardial phosphate metabolism of four patients with acute anterior myocardial infarction after coronary angioplasty and drug therapy was evaluated with cardiac-gated phosphorus magnetic resonance (MR) depth-resolved surface coil spectroscopy (DRESS) 5-9 days after the onset of symptoms. Significant reductions (about threefold) in the phosphocreatine (PCr) to inorganic phosphate (Pi) ratio and elevations in the Pi to adenosine triphosphate (ATP) ratio were observed in endocardially or transmurally derived MR spectra when compared with values from epicardially displaced spectra and values from seven healthy volunteers (P less than .05). High-energy phosphate metabolites and Pi ratios did not vary significantly during the cardiac cycle in healthy volunteers. However, contamination of Pi resonances by phosphomonoester components, including blood 2,3-diphosphoglycerate, precluded accurate spectral quantification of Pi and pH. The results indicate that localized P-31 MR spectroscopy may be used to directly assess cellular energy reserve in clinical myocardial infarction and to evaluate metabolic response to interventions.

Experimental studies have suggested that nonionic contrast agents are less nephrotoxic than ionic contrast agents. To examine the relative nephrotoxicity of the two types of agents, we randomly assigned 443 patients to receive either iopamidol (nonionic) or diatrizoate (ionic) for cardiac catheterization. The patients were stratified into low-risk (n = 283) or high-risk (n = 160) groups, on the basis of the presence of diabetes mellitus, heart failure, or preexisting renal insufficiency (base-line serum creatinine level, greater than 133 mumol per liter). Serum and urine analyses were performed at base line and 24 and 48 hours after the infusion of contrast material. Nephrotoxicity was defined as an increase in the serum creatinine level within 48 hours of at least 44 mumol per liter. The median maximal rise in the serum creatinine level was 18 mumol per liter in both the diatrizoate group (n = 235) and the iopamidol group (n = 208) (P not significant; power to detect a difference greater than 9 mumol per liter, greater than 90 percent). Creatinine levels increased by at least 44 mumol per liter (0.5 mg per deciliter) in 10.2 percent of the patients receiving diatrizoate and 8.2 percent of the patients receiving iopamidol (P not significant). Among the high-risk patients, creatinine levels increased by at least 44 mumol per liter in 17 percent of the patients in the diatrizoate group, as compared with 15 percent of the patients in the iopamidol group (P not significant). We were unable to demonstrate a difference in the incidence of nephrotoxicity between patients receiving a non-ionic contrast agent and those receiving an ionic contrast agent.

SG. Two-dimensional echocardiographic features of coronary arteriovenous fistula. AM HEART J 1982;104:872. 6. Agatston AS, Chapman E, Hildner FJ, Samet P. Diagnosis of a right coronary artery-right atrial fistula using two-dlmensional and Doppler echocardiography. Am J Cardiol 1984; 54~238. 7. Miyatake K, Okamoto M, Kinoshita N, Fusejima K, Sakakibara H, Nimura Y. Doppler echocardiographic features of coronary arteriovenouse fistula-complementary roles of cross-sectional echocardiography and the Doppler technique. Br Heart J 1984;51:508. 8. Goldman ME. Real-time two-dimensional Doppler flow imaging: a word of caution. J Am Coll Cardiol 1986;7:89. 9. Miyatake H, Izumi S, Okamoto M, Kinoshita N, Asonuma H, Nakagawa H, Yamamoto K, Takamyta M, Sakakibara H, Nimura Y. Semiquantitative grading of severity of mitral regurgitation by real-time two-dimensional Doppler flow imaging technique. J Am Co11 Cardiol 1986$82.

“Atheromatous emboli” is a general description for embolization of any atheromatous material. The term “atheroemboli” is used to refer to the dislodgement of vascular plaque material that contains cholesterol crystals plus red blood cells and fibrin. These can occlude major systemic vessels

To assess the time course and magnitude of change in left ventricular (LV) wall stress and ejection performance indices, 24 patients undergoing aortic valve replacement (AVR) for aortic stenosis were prospectively evaluated. Each patient underwent resting radionuclide angiography (RNA), echocardiography, and cardiac catheterization (high fidelity pressure) before AVR, then RNA and echocardiogram at one week and six months after AVR. Patients were stratified by preoperative ejection fraction (EF) into reduced EF (l50%) and normal EF (≥50%) groups. Pre-operatively, peak positive dp/dt was lower in the reduced EF group (1300 vs 1700 mmHg/sec, p = 0.035), and wall stress was elevated similarly in both groups (p = NS). Temporal Relationships of EF and Wall Stress Pre-op 1 Week 6 Mos Normal EF (n = 14) Mean Ejection Fraction (%) 66 64 68 Mean Wall Stress (dyne/cm 2 × 10 3 ) 62 34 44 Reduced EF (n = 10) Mean Ejection Fraction (%) 38 37 57 Mean Wall Stress (dyne/cm 2 × 10 3 ) 78 52 61 Wall stress was reduced at one week post-operatively (p l 0.005) in both groups. Ejection fraction remained depressed in the reduced EF group. By six months, however, EF had dramatically improved in the reduced EF group (p = 0.002). Conclusion In patients with LV dysfunction, EF remains low one week after AVR despite rectification of afterload mismatch. At six months, however, ejection performance improves. Therefore, when measured by ejection phase indices, the surgical benefit from AVR is not evident until late post-operatively.

Purpose Digital image compression is a means of reducing storage and exchange requirements for coronary angiograms. In order to assess the diagnostic accuracy of image compression, digital coronary arteriograms were analyzed in compressed and noncompressed formats. Methods The effect on visual assessment of stenosis severity of digital coronary angiograms was evaluated on a set of 100 image sequences using lossy (15: 1) Joint Photographic Experts Group (JPEG) compression software. A panel of 3 angiographers reviewed 6200 frames from 10 clinical exams both with and without standard JPEG compression. Original and compressed versions of each sequence were viewed in random order by all panel members blinded to compression status. Images were viewed on the same display used for digital acquisition with the Philips Digital Cardiac Imaging (DCI) System. Panelists identified and graded severity of 99 stenoses in quartiles with g50% considered to be significant. Results There was no significant difference in the number of lesions identified with each modality. Overall agreement for severity of all lesions between compressed and non-compressed modalities was 0.60 and Kappa = 0.52. If lesions were dichotomized into “significant” (g50%) or “insignificant” (≤50%), agreement was 0.94 and Kappa = 0.88, suggesting that when disagreement occurred, it tended to be within one severity grade. These agreement statistics are consistent with previously reported intra-observer variability in the review of cine-coronary angiograms. Conclusions The significant reduction in digital storage and exchange requirements provided by lossy JPEG does not result in a decrease in diagnostic quality of digital coronary angiograms. Variability in visual assessment from original and compressed data formats is comparable to intra-observer variability from identical data formats. Therefore, JPEG compression does not result in loss of diagnostic information and is a valid means of reducing storage and exchange requirements of coronary angiograms.

Study objective To determine the incidence of cardiovascular and renal toxicity of a nonionic contrast agent when used for cardiac catheterization, and to assess the value of electrolytes and urinalysis results as predictors of nephropathy induced by a contrast agent. Study design Nonrandomized trial using a criterion standard and a cohort analytic study with a 48-hour follow-up. Setting Referral-based university hospital. Patients Convenience sample of patients having diagnostic cardiac catheterization. Renal function and clinical status were evaluated at baseline in 1,144 patients; at 24 hours in 1,077 (94%); and at 48 hours in 663 (57%). Interventions After patients received saline for hydration, coronary angiography and left ventriculography were done with iopamidol (average dose, 203 +/- 56 cc). Measurements and main results The definite and possible incidence of major acute cardiovascular complications from nonionic contrast media was 0.2% and 0.7%, respectively. The mean serum creatinine level increased 11.5 mumol/L from baseline at 24 hours (P less than 0.0001) and 16.8 mumol/L from baseline at 48 hours (P less than 0.0001). Results in a randomly selected training sample were studied to determine predictors of a rise in serum creatinine of 44.2 mumol/L or more. The baseline serum creatinine level and age were significant predictors of renal injury, but hypertension, diabetes mellitus, congestive heart failure, vascular disease, the volume of contrast agent injected or baseline values of urinary variables did not predict nephrotoxicity. In an independent validation sample, only the baseline serum creatinine level was confirmed as a predictor of nephrotoxicity, whereas age was not. A model that predicted contrast-induced nephropathy by the serum creatinine level showed an exponential increase in the risk for nephrotoxicity if the baseline level was 106.1 mumol/L or higher. Conclusions Patients have a small but significant rise in serum creatinine after cardiac catheterization with a nonionic contrast agent. Baseline renal insufficiency is the only confirmed predictor of nonionic contrast-induced nephrotoxicity.

BackgroundAlthough seratonin has been postulated as an etiologic agent in the development of carcinoid heart disease, no direct evidence for different ambient serotonin levels in cardiac and noncardiac patients has been reported to date.Methods and ResultsThe present study reviews the experience with 604 patients in the Duke Carcinoid Database. Nineteen patients with proven carcinoid heart disease (by cardiac catheterization and/or echocardiography) were compared with the remaining 585 noncardiac patients in the database with regard to circulating serotonin and its principle metabolite. 5-hydroxyindoleacetic acid (5-HIAA). No significant demographic differences existed between the cardiac and noncardiac groups; however, typical carcinoid syndrome symptoms (i.e. flushing and diarrhea) were almost threefold more common in the cardiac group (p