Comparison of preload recruitable stroke work, end-systolic pressure-volume and dP/dtmax-end-diastolic volume relations as indexes of left ventricular contractile performance in patients undergoing routine cardiac catheterization.

The end-systolic pressure-volume relation, the relation between stroke work and end-diastolic volume, termed the preload recruitable stroke work relation, and the relation between the peak of the first derivative of left ventricular pressure (dP/dtmax) and end-diastolic volume have been employed as linear indexes of left ventricular contractile performance in laboratory animals. The purpose of this study was to examine the relative utility of these indexes during routine cardiac catheterization in seven human subjects (mean age 48 +/- 18 [SD] years) with a normal left ventriculogram and coronary angiogram. Left ventricular pressure was recorded continuously with a micromanometer catheter, and left ventricular volume was derived from digital subtraction contrast ventriculograms obtained at 30-ms intervals. Transient occlusion of the inferior vena cava with a balloon-tipped catheter was employed to obtain beat to beat reductions in left ventricular pressure and volume over 8.7 +/- 1.7 cardiac cycles. Stroke work declined by 49 +/- 13% during vena caval occlusion, but end-systolic pressure fell by only 26 +/- 11%, and changes in dP/dtmax were small and inconsistent (12 +/- 22%). Consequently, the range of data available for determination of the preload recruitable stroke work relation greatly exceeded that for the end-systolic pressure-volume relation and the dP/dtmax-end-diastolic volume relation, and much less linear extrapolation from the measured data was required to determine the volume-axis intercept. Preload recruitable stroke work relations were highly linear (r = 0.95 +/- 0.07), and much more so than end-systolic pressure-volume relations (r = 0.79 +/- 0.23).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in left ventricular diastolic performance after aortic balloon valvuloplasty: acute and late effects.

To evaluate acute and follow-up changes in left ventricular diastolic performance, simultaneous digital left ventriculography and micromanometry were performed in 49 patients undergoing aortic balloon valvuloplasty. All patients improved symptomatically after valvuloplasty, and 26 returned 6.3 +/- 1.5 months later for follow-up catheterization. Immediately after valvuloplasty, aortic valve area increased (before 0.5 +/- 0.2 versus after 0.8 +/- 0.2 cm2, p less than 0.01), cardiac output (before 4.3 +/- 1.2 versus after 4.4 +/- 1.3 liters/min) and ejection fraction (before 51 +/- 18% versus after 52 +/- 17%) did not change and diastolic indexes worsened, signified by a decrease in peak filling rate (before 247 +/- 80 versus after 226 +/- 78 ml/s, p less than 0.01) and increase in the time constant of isovolumetric relaxation (tau) (before 78 +/- 29 versus after 96 +/- 40 ms, p less than 0.01) and the modulus of chamber stiffness (before 0.107 +/- 0.071 versus after 0.141 +/- 0.083, p less than 0.01). At follow-up catheterization, 16 patients continued to have symptomatic improvement (group 1) and 10 had recurrence of symptoms (group 2). Aortic valve area, cardiac output and ejection fraction at follow-up catheterization in both groups were similar and unchanged from values before valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Serial left ventricular performance evaluated by cardiac catheterization before, immediately after and at 6 months after balloon aortic valvuloplasty.

Although impaired ventricular function has been shown to improve after aortic valve replacement, there are few data on hemodynamic changes after balloon aortic valvuloplasty based on follow-up catheterization. Of 71 patients surviving 6 months after balloon aortic valvuloplasty, 41 agreed to late recatheterization. All patients had pre- and postvalvuloplasty and 6 month catheterization data measured with high fidelity micromanometer pressure recordings and simultaneous digital subtraction left ventriculography. The hemodynamic result immediately after valvuloplasty included a reduction in the aortic valve gradient and a moderate increase in aortic valve area (0.51 +/- 0.14 to 0.81 +/- 0.19 cm2, p less than 0.0001). Ejection fraction increased slightly (52 +/- 18 to 55 +/- 17%, p less than 0.0001) despite a decrease in peak positive rate of rise of left ventricular pressure (dP/dt 1,650 +/- 460 to 1,500 +/- 490 mm Hg/s, p less than 0.05). There was also a decrease in left ventricular afterload and a small decrease in preload. At 6 month recatheterization, the mean aortic valve gradient and area were similar to baseline values, with 31 (76%) of 41 patients demonstrating valvular restenosis. At 6 months many left ventricular hemodynamic variables, including peak positive dP/dt and stroke work, also resembled prevalvuloplasty values. However, left ventricular end-diastolic volume was reduced (111 +/- 40 ml at 6 months versus 136 +/- 52 ml before valvuloplasty, p less than 0.01). The mean left ventricular ejection fraction was unchanged from prevalvuloplasty values in the study group of 41 patients, but was significantly improved in 9 of 15 patients with a baseline ejection fraction less than 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of coronary stenosis quantitation results from on-line digital and digitized cine film images.

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.

Accuracy of digital angiography for quantitation of normal coronary luminal segments in excised, perfused hearts.

The accuracy of coronary artery diameter determination by digital angiography was assessed by imaging 39 coronary segments of excised dog and human hearts and comparing these segments with pathologic sections 0.76 to 3.31 mm in luminal diameter. Digital images were obtained postmortem both during contrast injection using a fixed-pressure coronary perfusion system and after fixation when the coronary size was maintained by injection of a barium-gelatin casting mixture. Digital data were analyzed with commercially available, automated edge-detection software using a coronary catheter as the calibration standard. Coronary diameter measured during contrast injection was not significantly different from that measured after casting and fixation. Digital data from both methods correlated well with diameters from pathologic sections (injected, r = 0.85; fixed, r = 0.91). Linear regression parameters comparing pathologic diameters with the contrast injection method were slope = 0.82, intercept = 0.42 mm, and standard error of the estimate = 0.27 mm. Parameters for the comparison of pathology with casted coronary data were slope = 0.95, intercept = 0.16 mm, and standard error of the estimate = 0.23 mm. Intra- and interobserver variability were 3% (0.05 mm) and 4% (0.07 mm), respectively. These data indicate that when a coronary catheter as a calibration standard is used, coronary artery dimensions can be accurately measured by automated digital angiography techniques.

Prediction of early recurrent myocardial ischemia and coronary reocclusion after successful thrombolysis: a qualitative and quantitative angiographic study.

To determine the association of qualitative and quantitative measurements of the myocardial infarct-related coronary narrowing with subsequent recurrent ischemia/reocclusion after successful thrombolysis, 47 patients treated with high-dose (150 mg) tissue plasminogen activator over 6 to 8 hours were studied in the setting of acute myocardial infarction. No patient underwent emergent coronary angioplasty. All patients had Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow or higher at the baseline (90-minute) angiogram; 31 patients had a protocol 24-hour catheterization as well. Eighteen patients had recurrent ischemia/reocclusion whereas 29 had an uneventful hospital course. There was no significant difference in baseline clinical characteristics between the 2 groups. Twenty-five (86%) of those with an uneventful course had TIMI grade 3 flow at baseline angiogram compared with 56% of patients with recurrent events. No significant difference in angiographic morphologic characteristics was found between the 2 groups at baseline catheterization. At 24 hours, however, none of the patients who subsequently had recurrent events had a concentric narrowing, while 13 (58%) of them had a complex morphology. In contrast, quantitative parameters of minimal lumen diameter, percent area stenosis and percent diameter stenosis at baseline and 24 hours were not significantly different between those who did and did not have recurrent ischemia/reocclusion. These findings suggest that the degree and quality of coronary flow at baseline catheterization are more important determinants of sustained patency and event-free hospitalization than are quantitative dimensions or coronary morphology. In addition, narrowings that fail to become concentric within the first 24 hours are more likely to be associated with subsequent ischemia or reocclusion during the early periinfarct period.

Early and late changes in left ventricular systolic performance after percutaneous aortic balloon valvuloplasty.

To evaluate early and late hemodynamics after aortic valvuloplasty, 17 patients underwent first-pass radionuclide angiocardiography with simultaneous high-fidelity micromanometer pressure before, 10 minutes after and 6 months after aortic valvuloplasty. Pressure-volume and stress data were assessed. Immediately after the procedure, no significant change was observed in heart rate, systemic blood pressure, cardiac output or aortic insufficiency (as measured by visual or quantitative aortography). The mean and peak transvalvular gradient decreased from 64 to 36 mm Hg (p less than 0.001) and 76 to 38 mm Hg (p less than 0.001), respectively. The mean aortic valve area increased from 0.5 to 0.8 cm2 (p less than 0.001). Using echocardiography, meridional end-systolic wall stress decreased from 81 to 63 x 10(3) dynes/cm2 (p less than 0.001). Left ventricular ejection fraction increased from 0.48 to 0.54 (p less than 0.01), end-diastolic volume decreased from 161 to 143 ml (p less than 0.001) and end-diastolic pressure decreased from 18 to 13 mm Hg (p less than 0.01). Left ventricular stroke work (the area of the pressure-volume loop) also decreased from 17.5 to 14.7 x 10(6) ergs (p less than 0.001). The loop shifted to the left and downward. At the 6-month study, the mean and peak aortic valve gradient increased from 36 to 56 mm Hg (p less than 0.001) and 38 to 61 mm Hg (p less than 0.001), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in left ventricular systolic performance immediately after percutaneous aortic balloon valvuloplasty.

To evaluate the acute changes in left ventricular (LV) performance before and immediately after percutaneous aortic valvuloplasty, 25 patients underwent first-pass radionuclide angiocardiography for construction of pressure-volume loops. Simultaneously, high-fidelity micromanometric aortic and LV pressures were recorded. Echocardiographic wall thickness was used to define wall stress. After valvuloplasty, no acute changes were observed in the heart rate, aortic systolic pressure, cardiac output or degree of aortic insufficiency. Valvuloplasty decreased the peak aortic valve gradient from 73 to 40 mm Hg (p less than 0.001) and the mean gradient from 61 to 30 mm Hg (p less than 0.001); aortic valve area increased from 0.55 to 0.80 cm2 (p less than 0.001). Meridional end-systolic wall stress decreased from 83 to 55 X 10(3) dynes/cm2 (p less than 0.01). LV ejection fraction increased from 0.41 to 0.48 (p less than 0.01). LV end-diastolic volume decreased from 186 to 160 ml (p less than 0.001), end-systolic volume decreased from 115 to 87 ml (p less than 0.001) and end-diastolic pressure decreased from 22 to 17 mm Hg (p less than 0.01). LV stroke work decreased from 16.0 to 14.0 X 10(6) erg (p less than 0.001). No change was observed in peak positive LV dP/dt or the end-systolic pressure-volume ratio. This study documents variable and complex changes in the measures of cardiac function after aortic valvuloplasty. A decrease in the amount of LV outflow obstruction with maintenance of the cardiac output at a decreased level of LV filling occurs.

Doppler left ventricular diastolic filling abnormalities in aortic stenosis and their relation to hemodynamic parameters.

Doppler mitral flow indexes and their relation to invasively measured hemodynamic diastolic indexes were assessed in 13 patients with isolated aortic stenosis (AS), and compared to Doppler indexes in 10 normal subjects matched for age, heart rate, left ventricular (LV) ejection fraction and LV load. Patients with AS showed no difference in Doppler early filling (E) indexes, but demonstrated greater Doppler atrial filling (A) indexes in comparison to normal subjects: atrial velocity (89 +/- 31 vs 56 +/- 7 cm/s), atrial integral (11.4 +/- 4.8 vs 5.7 +/- 1.6 cm), A/E velocity (1.69 +/- 0.89 vs 1.06 +/- 0.26) and A/E integral (3.53 +/- 6.64 vs 0.81 +/- 0.27) (all p less than 0.05). Doppler indexes in patients with AS did not correlate with hemodynamic indexes of LV relaxation or chamber stiffness. Significant correlations were observed between Doppler and angiographic peak filling rates (r = 0.70) and between Doppler atrial filling velocity and LV end-diastolic volume (r = -0.66), LV end-diastolic pressure (r = -0.48) and LV ejection fraction (r = 0.53) (all p less than 0.05). These data indicate that, compared to matched normal subjects, most patients with AS have an increased atrial contribution to LV filling. However, in patients with decreased LV function, atrial function may also be depressed, as indicated by a decreased atrial contribution to LV filling, resulting in "normalization" of the Doppler mitral flow pattern.

Lysis of a left ventricular thrombus with recombinant tissue plasminogen activator.

A 23-year-old woman with peripartum cardiomyopathy presented with a 2.1 x 2.5-cm pedunculated, mobile, left ventricular thrombus and evidence of systemic embolization. Due to the patient's poor left ventricular function, thrombectomy was not a viable option. Treatment with high-dose IV heparin was initially utilized but was unsuccessful as the thrombus appeared to enlarge on echocardiography. An accelerated weight-adjusted dose of recombinant tissue plasminogen activator (rt-PA) successfully lysed the thrombus without evidence of embolization. Although rt-PA has been used for primary lysis of high-risk ventricular thrombi, this is the first documentation of successful lysis of a left ventricular thrombus in a patient with peripartum cardiomyopathy.

A clinical comparison of mitral valve repair versus valve replacement in ischemic mitral regurgitation.

Severe mitral regurgitation caused by acute myocardial infarction has been a particularly difficult management problem with disappointing clinical results. Over a 75-month period, ending March 31, 1987, 611 patients underwent mitral valve operations at Duke University Medical Center. Within this group, 55 patients had clearly defined ischemic mitral regurgitation, and 37 of these required emergency operations. Thirty-one of the 55 patients had isolated posterior papillary muscle dysfunction, nine had papillary muscle rupture, and 15 had severe ventricular dysfunction and generalized annular dilatation. Thirty-two patients were treated with primary mitral valve replacement, and 23 had mitral valve repair. In 18, repair was accomplished by a transventricular approach, combining the techniques of commissural annuloplasty, papillary muscle shortening or reimplantation, and infarct exclusion. Transventricular mitral valve repair proved to be safe, expeditious, and effective in restoring valve competence. Although the repair and replacement groups were similar with respect to all relevant baseline characteristics, improved operative survival was observed after valve repair, as compared to replacement, both for the overall group (p = 0.03) and for acute papillary muscle dysfunction (p = 0.05). These data suggest that a policy of predominant mitral valve repair, when appropriately applied in patients with ischemic mitral regurgitation, offers the potential for improving therapeutic results.

Elevated potassium intake inhibits neointimal proliferation in the swine coronary artery.

BACKGROUND: Previously, we reported that elevated extracellular potassium concentration in vitro inhibited proliferation and migration of vascular smooth muscle cells, formation of free radical compounds by macrophages, and reduced platelet sensitivity to agonists. More recently, we described a reduction in neointimal proliferation after balloon angioplasty injury in the carotid arteries of rats associated with an elevation of dietary potassium intake during a 4-week experiment. In the present study we conducted a similar investigation in the swine coronary artery balloon angioplasty model. PROCEDURES: Two groups of seven castrated male swine were studied; for 28 days the normal potassium group consumed a diet containing 0.25% potassium and the high potassium group ate diet containing 2.0% potassium. After 14 days on the diet, balloon angioplasty was performed. After an additional 14 days on the same diets the hearts were removed, and normal and lesioned sections of the artery were analyzed histologically. RESULTS: The neointimal area was markedly less in the high potassium group than in the normal potassium group, 0.33+/-0.04 mm2 v 0.74+/-0.10 mm2 (P < .004). Neointimal area-to-total wall area ratio in the normal potassium group averaged 0.199+/-0.018, significantly greater than the ratio computed for the elevated potassium group, 0.120+/-0.015 (P < .006). CONCLUSION: These results support the hypothesis that a high level of dietary potassium intake inhibits neointimal proliferation after balloon angioplasty in the swine coronary artery.

Rate-related left bundle branch block with chest pain and normal coronary arteriograms treated by exercise training.

A clinical observation of chest pain associated with the onset of rate-related left bundle branch block has been described in patients with normal coronary arteriograms. The authors used standard cardiac rehabilitation techniques for exercise training in a 47-year-old woman with these manifestations. Serial treadmill tests revealed that during the course of 3 months of exercise training, the heart rate at onset of LBBB gradually rose from 133 to 175 beats per minute, and she no longer developed symptoms during her routine daily activities or exercises. Exercise training was a successful nonpharmacologic strategy that delayed the onset of rate-related LBBB and chest pain in this patient and avoided the need for beta blocker therapy.

Plasma oxidase assay for screening of myocardial infarction.

The availability of techniques such as surgical reperfusion, angioplasty, and thrombolysis for the treatment of acute myocardial infarction (AMI) has revived interest in seeking an early detectable biochemical marker diagnostic for AMI. Therefore, we investigated whether an unidentified oxidase that is released by activated neutrophils at the onset of AMI could be used as an early diagnostic assay. The conversion by plasma oxidase of 1 microM of adrenaline to 1 microM of adrenochrome represents the plasma oxidase activity (POA) of 1 U/L. Fifty patients suspected of having AMI, 40% of whose electrocardiograms were nondiagnostic for AMI, were admitted to the coronary care unit, and venous blood samples were obtained for determination of the POA and creatine phosphokinase-MB levels. Healthy volunteers (n = 12) served as control subjects, and 8 patients with pneumonia whose leukocyte counts were greater than 15,000 microL were included in the study. In those with AMI (n = 22), as determined by serial creatine phosphokinase-MB, the mean POA (+/- standard error of the mean) was 233 +/- 13 U/L, and in those with angina and no AMI (n = 28) was 127 +/- 5 U/L (P < 0.0001). In the control group, mean POA (+/- standard error of the mean) was 84 +/- 5 U/L (control versus angina; P < 0.01) and for those with infection was 214 +/- 10 U/L. At admission, the creatine phosphokinase-MB was diagnostic for only 12 of the 22 patients with AMI (sensitivity rate of 54%), whereas in 21 of those patients, the POA values were diagnostic for AMI (sensitivity rate of 95%).(ABSTRACT TRUNCATED AT 250 WORDS)

Thromboembolism in the right side of the heart.

Right-sided cardiac thromboemboli, or pulmonary emboli-in-transit, represent an unusual disease process with high morbidity and mortality. We present a detailed case report and a synopsis of our experience at the University of Mississippi Medical Center between 1990 and 1997 and review the current medical literature. These thrombi and emboli may largely be subdivided into type A--a mobile, serpiginous clot that is probably a mobilized deep vein thrombus--and type B--a rather immobile clot morphologically similar to left-sided heart thrombi that may represent intracardiac thrombosis. The mainstays of therapy include surgical embolectomy and thrombolysis, but there is no clear benefit of one over the other. Treatment should be individualized according to the clot's size and morphology, likelihood of preexisting pulmonary embolism, the patient's cardiopulmonary reserve, comorbid conditions, and local expertise with treatment modalities.

Problems in the recognition of aortoembolic stroke.

Recent reports suggest aortoembolism is an important cause of stroke. Although transesophageal echocardiography visualizes the aortic arch, diagnosis of aortoembolism stroke is not common. We investigated reasons for this discrepancy at our institution. We reviewed charts and transesophageal echocardiography videotapes of 16 patients with recent ischemic stroke or transient ischemic attack who had undergone transesophageal echocardiography. For each patient, we determined the most likely cause of cerebral ischemia, and we compared the official transesophageal echocardiography report to our interpretation of the videotape. In our videotape review, 13 patients had good visualization of the aortic arch. Of 6 patients with atherosclerosis in the arch, 1 had high-grade carotid stenosis, 1 had atrial fibrillation, 1 had "small-vessel disease," and 3 had cerebral ischemia of unknown cause. The official reports did not mention aortic arch disease in 4 of 6 patients. A possible cause of cerebral ischemia was identified in 6 of 7 patients with normal aortic arches. Of 3 patients who had poor visualization of the aortic arch, one had "small-vessel disease," and 2 had ischemic stroke of unknown cause despite extensive workups. We conclude that aortic arch disease is common in patients with ischemic stroke and transient ischemic attack and may be a cause of cerebral ischemia, especially in patients with stroke or transient ischemic attack due to small-vessel occlusion or of unknown cause. Aortic arch disease may not be identified as the cause of stroke or transient ischemic attack because (a) transesophageal echocardiography is not done, (b) transesophageal echocardiography is done but the aortic arch is not visualized, (c) transesophageal echocardiography is done, the aortic arch is visualized, but the examiner does not comment on aortic arch disease, or (d) despite transesophageal echocardiography identification of arotic arch disease, the treating physician does not consider the aorta to be a potential source of embolization.

Hemodynamic effects of fructose 1,6-diphosphate in patients with normal and impaired left ventricular function.

We compared the short-term hemodynamic effects of intravenous fructose 1,6-diphosphate (FDP) administration in patients with coronary artery disease. Hemodynamic measurements were performed before and after administration of FDP in two groups of patients: those with impaired left ventricular (LV) function, elevated LV end-diastolic pressures (LVEDP > or =12 mm Hg, n = 30), and those with normal LV function (LVEDP <12 mm Hg, n = 17). In those with impaired LV function, FDP induced a decrease in LVEDP from 22 +/- 1.31 to 16.73 +/- 1.46 mm Hg (p< 0.0001). The cardiac index increased (2.50 +/- 0.11 to 2.81 +/- 0.13 L/m2 [p < 0.0001]), as did the LV stroke work index (31.7 +/- 2.04 to 40.3 +/- 2.67 gm x m x m2 [p < 0.0001]). FDP induced no significant change in heart rate and mean aortic pressure. Pulmonary pressure and resistance declined (p<0.002 and p< 0.0001, respectively). Systemic vascular resistance decreased because of increased cardiac output and unchanged arterial pressure (p < 0.001). In those patients with normal baseline LVEDP (5.06 +/- 0.27 mm Hg), FDP decreased heart rate (p< 0.0001) and systemic and pulmonary resistance (p < 0.03 and p < 0.004, respectively), whereas LVEDP and mean aortic and pulmonary pressures remained unchanged. FDP moderately increased cardiac output (p < 0.05), stroke volume index, and LV stroke work index (p< 0.002 and p< 0.003, respectively). The observed improvement in LV function in those patients with elevated LV filling pressures is thought to be a result of an increased energy production by the Embden-Meyerhoff pathway and to act as a positive inotrope.