Time-stretched multi-hit 3D velocity map imaging of photoelectrons.

The 2D photoelectron velocity map imaging (VMI) technique is commonly employed in gas-phase molecular spectroscopy and dynamics investigations due to its ability to efficiently extract photoelectron spectra and angular distributions in a single experiment. However, the standard technique is limited to specific light-source polarization geometries. This has led to significant interest in the development of 3D VMI techniques, which are capable of measuring individual electron positions and arrival times, obtaining the full 3D distribution without the need for inversion, forward-convolution, or tomographic reconstruction approaches. Here, we present and demonstrate a novel time-stretched, 13-lens 3D VMI photoelectron spectrometer, which has sub-camera-pixel spatial resolution and 210 ps (σ) time-of-flight (TOF) resolution (currently limited by trigger jitter). We employ a kHz CMOS camera to image a standard 40 mm diameter microchannel plate (MCP)/phosphor anode detector (providing x and y positions), combined with a digitizer pick-off from the MCP anode to obtain the electron TOF. We present a detailed analysis of time-space correlation under data acquisition conditions which generate multiple electrons per laser shot, and demonstrate a major advantage of this time-stretched 3D VMI approach: that the greater spread in electron TOFs permits for an accurate time- and position-stamping of up to six electrons per laser shot at a 1 kHz repetition rate.

Iron deficiency anemia and cardiac mortality in patients with left ventricular systolic dysfunction undergoing coronary stenting.

AIM: The aim of this study was to assess cardiac mortality in patients with reduced ejection fraction (EF< or =45%) and anemia (Hb< or =12 g/dL) undergoing coronary stenting and to investigate whether iron-deficiency anemia influenced outcome when compared to non-anemic patients or patients with other types of anemia. METHODS: One hundred twenty consecutive patients undergoing percutaneous coronary intervention (PCI) between April 2003 and December 2005 were identified and followed for a median of 30 months. Patients were divided into 2 groups, anemic (Hb< or =12 g/dL) and non-anemic. Anemic patients were then divided into 3 sub-groups based on laboratory analysis and anemia work-up: iron-deficiency, malignancy-associated, and anemia of chronic disease (including chronic kidney disease). Mortality rates and cause of death were retrieved using both the Social Security database and the hospital records. RESULTS: Thirty-one percent of patients had iron deficiency, 24% had a malignancy-associated anemia and 45% had anemia of chronic disease. Overall mortality was 12% of which 29% was cardiac death. All-cause and cardiac mortality were significantly higher in anemic vs. non-anemic patients, (31% vs. 6%, P<0.001, and 10% vs. 1%, P=0.016, respectively). Iron-deficiency anemia strongly predicted cardiac mortality (33% vs. 1% in non-anemic patients, P<0.001), while malignancy-associated anemia was the strongest predictor of non-cardiac death (57% vs. 4% in non-anemic patients, P<0.001). Anemia of chronic disease neither predicted cardiac nor non-cardiac death. CONCLUSIONS: To the authors' knowledge, this is the first study to show that iron-deficiency anemia is a strong predictor of cardiac death when compared to patients with other types of anemia or to non-anemic patients.

Use of routine functional testing after percutaneous transluminal coronary angioplasty: results from the ROSETTA Registry.

BACKGROUND: The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for exercise testing suggest that only selected groups of high-risk patients should undergo routine functional testing after percutaneous transluminal coronary angioplasty (PTCA) for the detection of restenosis. OBJECTIVES: Our purpose was (1) to document the patterns of use of post-PTCA functional testing and (2) to determine whether the choice of functional testing strategy is related to clinical characteristics of patients or whether physicians use a similar strategy for all their patients. METHODS: The Routine Versus Selective Exercise Treadmill Testing After Angioplasty (ROSETTA) Registry is a prospective study examining the use of functional testing among 788 patients at 13 centers in 5 countries. RESULTS: During the 6-month period after a successful PTCA, 49% of patients underwent functional testing (range among centers 10%-81%). Among patients who underwent functional testing, 39% had a clinical indication and 61% had functional testing as a routine follow-up. The first functional test was performed a median of 7 weeks after PTCA, with 13% of patients having second tests at a median of 14 weeks and 4% having additional tests at a median of 20 weeks. Univariate and multivariate analyses demonstrated that the chief determinant of the use of routine functional testing was clinical center. Aside from age (P <.0001), no baseline clinical or procedural characteristics were consistently associated with the use of routine functional testing after PTCA. CONCLUSIONS: Physicians do not appear to be adhering to the ACC/AHA guidelines for exercise testing regarding the routine use of post-PTCA functional testing. None of the clinical characteristics identified by the ACC/AHA guidelines were associated with the routine use of post-PTCA functional testing, and the primary determinant of functional testing was the location of the center at which the patient had the PTCA.

Therapeutic embolization for unusual latrogenic complications related to coronary revascularization.

Percutaneous therapeutic embolization may be an effective strategy to manage distal coronary perforations or inadvertent iatrogenic coronary arteriovenous fistula complicating revascularization procedures. We present two cases in which embolization techniques were used to manage these patients and avoid the need for surgical intervention.

Fluoroscopy and selective angiography of left ventricular assist system inflow cannula as a method of detecting cannula entrapment.

Left ventricular assist systems have become an important tool as a bridge to cardiac transplantation. Malfunction of these devices often leads to clinical and hemodynamic deterioration. One potential complication is the obstruction of the inflow cannula secondary to remodeling of the left ventricular cavity. We report two cases where fluoroscopy and selective angiography were used to visualize the orientation and obstruction of the inflow cannula when echocardiographic findings were indeterminant.

Absence of parasympathetic control of heart rate after human orthotopic cardiac transplantation.

BACKGROUND: Partial reinnervation of cardiac sympathetic nerves has been observed after heart transplantation; we hypothesized that parasympathetic control to the heart after transplantation may return as well. To test this hypothesis, we examined heart rate responses produced by two cardiovascular reflexes whose efferent limbs are subserved by vagal fibers to the heart: (1) trigeminal reflex (simulated diving reflex) and (2) arterial baroreflex with phenylephrine injection. METHODS AND RESULTS: An "early" group (n=31, <24 months after transplantation) and a "late group" (n=27, >45 months after transplantation) were studied and compared with a control group with intact cardiac innervation (n=32) and a renal transplant group with similar transplant immunosuppressive regimen (n=11). For trigeminal reflex testing, responses of the donor sinus node (DSN) (sinus node controlling heart rate) and recipient sinus node (RSN) in the innervated remnant right atrium in cardiac transplant patients were compared with heart rate responses in the control groups. For arterial baroreflex testing, baroreflex gains for the DSN and RSN in the cardiac transplant groups were compared with those of the control group. With engagement of the trigeminal reflex, the DSN rate of both transplant groups changed minimally (early, 1.2+/-1.2 bpm; late, 1.8+/-2.5 bpm) compared with the expected decrease in control subjects (-19.8+/-3.0 bpm) and renal transplant patients (-23.9+/-4.9 bpm) (P<.001 versus cardiac transplants). Changes in the RSN rate of both cardiac transplant groups (early, -13.0+/-4.0 bpm; late, -10.0+/-3.7 bpm) were similar to the control groups. Arterial baroreflex gains for the DSN were also depressed (early, 0.1+/-0.2 ms/mm Hg; late, 0.2+/-0.2 ms/mm Hg) compared with control (14.9+/-1.8 ms/mm Hg) and RSN (early, 9.9+/-1.3 ms/mm Hg; late, 10.9+/-1.3 ms/mm Hg; P<.001 versus DSN transplant). CONCLUSIONS: These data suggest that parasympathetic influences on donor heart rate are absent in the majority of patients up to 96 months after cardiac transplantation.

Evidence against reinnervation of cardiac vagal afferents after human orthotopic cardiac transplantation.

BACKGROUND: Orthotopic cardiac transplantation results in total cardiac denervation. Recent studies in humans suggest that reinnervation of cardiac sympathetic nerves (cardiac efferents) may occur after cardiac transplantation. We hypothesized that reinnervation of cardiac afferents may occur as well. To test this hypothesis, we investigated reflex responses produced by stimulation of ventricular chemosensory endings subserved by vagal afferents (cardiac depressor reflex). METHODS AND RESULTS: Two cardiac transplant groups were studied: an "early" group (n = 18, < 24 months after transplant) and a "late" group (n = 18, > 43 months after transplant); these groups were compared with a control group with intact innervation (n = 18). The reflex response of the recipient sinus node (RSN) in the remnant right atrium, which remains innervated after transplantation, was observed during selective right coronary artery (RCA) and left coronary artery (LCA) injection of the radiographic contrast agent meglumine diatrizoate, which is known to stimulate ventricular chemosensory endings. A decrease in the rate of the RSN was expected if reinnervation of chemosensory endings had occurred and the afferent limb of the cardiac depressor reflex was intact. With injection, the RSN rate of both transplant groups did not decrease but increased (early: LCA, 7.2 +/- 1.4 beats per minute; RCA, 6.3 +/- 1.3 beats per minute; late: LCA, 5.9 +/- 1.0 beats per minute; RCA, 6.0 +/- 0.9 beats per minute) compared with the expected decrease in control patients (LCA, -20.8 +/- 2.5 beats per minute; RCA, -18.0 +/- 4.0 beats per minute; P < .001 versus transplants). Decreases in mean arterial pressure in the transplant groups (early: LCA, -11.3 +/- 1.4 mm Hg; RCA, -10.0 +/- 1.6 mm Hg; late: LCA, -13.0 +/- 1.6 mm Hg; RCA, -9.1 +/- 1.5 mm Hg) were less than those observed in the control group (LCA, -19.8 +/- 2.2 mm Hg; RCA, -18.7 +/- 4.0 mm Hg; P < .05 versus transplants). CONCLUSIONS: The results suggest that reinnervation of ventricular chemosensory endings subserved by vagal afferents in cardiac transplant patients does not occur up to 74 months after transplantation.

Histopathologic correlates of unstable ischemic syndromes in patients undergoing directional coronary atherectomy: in vivo evidence of thrombosis, ulceration, and inflammation.

Complex coronary morphologic abnormalities with thrombus and ulceration have been recognized in acute ischemic syndromes by angiography, angioscopy, and autopsy. However, in vivo histopathologic correlates of unstable ischemic syndromes have not been described. The purpose of this study was to characterize intracoronary lesion morphologic abnormalities by analyzing specimens excised by directional atherectomy in patients with different ischemic syndromes. Tissue specimens removed by directional coronary atherectomy of primary lesions in native vessels were matched blindly to the clinical status of 130 patients representing 43% of a consecutive directional coronary atherectomy population of 300 patients; 824 specimens (range per patient 1 to 30, mean 6.3) were obtained. Clinical subgroups were prospectively classified as recent myocardial infarction (< or = 15 days, mean 6, range 1 to 15 days), 48 patients; prolonged rest angina, 34 patients; crescendo angina, 29 patients; and stable angina, 19 patients. Shavings were prospectively analyzed for presence of thrombus, ulceration, or chronic inflammatory cells. Thrombus was observed in 33 (69%) patients with recent myocardial infarction, 17 (50%) with rest angina, 12 (41%) with crescendo angina, 7 (37%) with stable angina (p = 0.048). Plaque ulceration was identified in 12 (25%) patients with recent myocardial infarction, 4 (12%) with rest angina, 2 (7%) with crescendo angina, and 1 (5%) with stable angina (p = 0.09). Inflammatory cells were noted in the specimens of 32 (67%) patients with recent myocardial infarction, 16 (45%) with rest angina, 12 (41%) with crescendo angina, and 9 (45%) with stable angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Immediate results of interventional devices for coronary ostial narrowing with angina pectoris.

Angioplasty of aorto-ostial lesions has had suboptimal results. This study reports on the immediate results of new debulking devices (atherectomy, excimer laser) in the treatment of aorto-ostial disease. Thirty-one vessels (29 patients) with an ostial lesion treated with a new device (group I) were compared with 15 vessels (13 patients) with an ostial lesion treated with angioplasty alone during the preceding 24 months (group II). Both groups were similar in their clinical characteristics. A larger proportion of vessels in group I (64%) compared with group II (7%) had unfavorable features for angioplasty. Procedural success was similar: 28 vessels in group I (91%) and 14 in group II (93%). Among the new devices, success was also similar: atherectomy in 8 arteries (89%), rotablator in 4 (100%) and excimer laser in 17 (94%). The acute gain was more significant with new devices: absolute reduction in percent stenosis was 66% for directional atherectomy, 67% for rotational atherectomy (p = 0.016 compared with angioplasty), 52% for excimer laser (p = 0.09) and 46% for angioplasty. In group I, 2 patients (6%) required emergency bypass surgery during our early experience; no deaths or Q-wave myocardial infarctions occurred. Group II had no complications. Therefore in aorto-ostial lesions, despite a much higher prevalence of unfavorable angiographic characteristics, new devices had (1) a success rate of > or = 90%, (2) a significantly larger acute gain compared with angioplasty alone, and (3) an acceptable complication rate. Larger studies with complete angiographic follow-up are needed to assess restenosis.

Assessment of thallium scintigraphy and echocardiography during dobutamine infusion for the detection of coronary artery disease.

Dobutamine infusion was performed in 16 patients following cardiac catheterization, and non-invasive assessment was performed with thallium SPECT and echocardiography. Dobutamine thallium scintigraphy was abnormal in 93% of patients with significant coronary artery disease. In addition, individual epicardial vessel involvement was identified by a corresponding perfusion defect with 88% sensitivity and 93% specificity. Dobutamine echocardiography revealed segmental wall motion abnormalities in 62% of patients with significant coronary disease. However, in six patients baseline segmental wall motion abnormalities on echocardiography improved during dobutamine infusion. Dobutamine thallium SPECT is a safe and useful test for the detection and localization of coronary artery disease. Dobutamine echocardiography is less useful in screening for coronary disease, but may detect areas of abnormally functioning myocardium having retained viability.

Long-term efficacy of triple-vessel angioplasty in patients with severe three-vessel coronary artery disease.

Between May 1982 and December 1988, a total of 103 patients underwent angioplasty of all three major coronary arteries at a single institution. Angiographic success was achieved in 334 of 352 vessels (95%) and in 441 of 460 lesions (96%). No patients required urgent bypass surgery, and none died during the procedure; six had non-Q wave infarctions. The mean length of follow-up time was 49 +/- 15 months (range 28 to 107 months). There have been 11 deaths, and one patient has undergone cardiac transplantation. Thirty-six patients had a clinical recurrence; 30 had repeat angioplasty and five had bypass surgery. Another nine patients eventually had bypass surgery after the clinical recurrence. At 48 months actuarial event-free rates are myocardial infarction, 98%; bypass surgery, 88%; and death, 89%. Of 86 current survivors, 58 are in functional class O to I, 21 are in class II, and seven are in class III.

Frequency and predictors of left ventricular segmental dysfunction in patients with recent rest angina.

The relation between coronary artery lesion morphology and associated segmental left ventricular (LV) dysfunction in patients with unstable angina is unclear. Fifty-two patients with angina occurring at rest who underwent cardiac catheterization within 3 days of the last episode of pain and had no enzymatic evidence for myocardial necrosis were evaluated. Coronary artery narrowings deemed responsible for the ischemic episodes were analyzed with regard to the artery involved, maximal diameter of the narrowing, presence of thrombus, and complex appearance. Time to catheterization, age, sex and electrocardiographic evidence of ischemia were also noted. Segmental LV dysfunction in the territory supplied by the "culprit lesion" was present in 58% of patients. It occurred significantly more often with lesion location in the left anterior descending coronary artery, and was less frequent with lesions in the left circumflex and ramus coronary arteries. Ischemic electrocardiographic changes were more sensitive in predicting LV dysfunction with culprit lesion location in the left anterior descending or right coronary artery. LV dysfunction could not be predicted by any other parameter analyzed. It is concluded that postischemic LV dysfunction occurs frequently in rest angina, especially when the severest narrowing is in the left anterior descending coronary artery.

A technique to access severely diseased arteries.

Cardiac catheterization performed in patients with severe peripheral vascular disease may represent a difficult technical challenge and is associated with a higher incidence of vascular complications. We describe a technique that uses angioplasty equipment to access severely diseased arteries. This technique allows a percutaneous transluminal coronary angioplasty (PTCA) guide wire to be steered across vascular lesions under direct visualization of the lumen and continuous pressure monitoring, potentially reducing the risk of vascular complications.

Immediate and long-term results of delayed recanalization of occluded acute myocardial infarction-related arteries using coronary angioplasty.

Recent evidence suggests that late reperfusion of an occluded infarct-related artery after acute myocardial infarction (AMI) may convey a better prognosis. The clinical outcome of percutaneous transluminal coronary angioplasty (PTCA) as a means of mechanical reperfusion in this particular setting has not been clearly delineated. Ninety-seven patients with AMI underwent PTCA of the occluded infarct-related artery after the acute phase of the AMI (48 hours to 2 weeks, mean 8 +/- 4 days). The study consisted of 72 men (74%) (mean age 56.5 +/- 12 years) and 25 women. Seventy-seven patients (79%) had a Q-wave AMI and 20 patients (21%) a non-Q-wave AMI. Seventy-six patients (79%) had angina after AMI and 4 had previously undergone coronary bypass surgery. Clinical success was achieved in 85 patients (87%). Angiographic success was obtained in 90 of the 97 occluded arteries (93%) and was similar for all 3 major vessels: right coronary 97%, left anterior descending 93% and circumflex 85% (p = not significant). Major complications (AMI, emergency bypass and death) occurred in 3 patients (3.1%). Long-term follow up (3.7 +/- 0.8 years) revealed symptomatic recurrence in 20 (23%), whereas 51 (58%) remained asymptomatic. Most recurrences (16 of 20) were in the form of restenosis rather than reocclusion, with a high success rate for repeat dilation (93%). These results indicate that mechanical reperfusion of an occluded infarct artery, performing PTCA 48 hours to 2 weeks after AMI, has a high success rate, a low complication rate and low symptomatic restenosis.

Intracoronary urokinase as an adjunct to percutaneous transluminal coronary angioplasty in patients with complex coronary narrowings or angioplasty-induced complications.

The effectiveness of intracoronary urokinase infusion as an adjunct to percutaneous transluminal coronary angioplasty (PTCA) was studied in 50 patients who underwent angioplasty for complex coronary narrowings or had thromboembolic complications during PTCA (29 [58%] men, 3 [6%] stable and 37 [74%] unstable angina, and 16 [32%] prior coronary bypass surgery). The primary indications for intracoronary urokinase infusion were intracoronary thrombus in 27 patients (54%), distal coronary embolization in 9 (18%), and abrupt reclosure in 14 (28%). Urokinase was infused in a mean (+/- standard deviation) dosage of 399,000 +/- 194,000 IU (range 150,000 to 1,000,000) at an average rate of 5,000 to 20,000 IU/min. Angiographic success was achieved in 43 patients (86%). Complications included the need for urgent bypass surgery in 3 patients, Q-wave myocardial infarction in 2, and non-Q-wave myocardial infarction in 12 (8 of whom had peak creatine kinase less than twice the upper normal limit). The incidence of myocardial infarction was significantly higher in patients with vein grafts (69%) than in those with PTCA of native vessels (14%). Two patients died (1 massive gastrointestinal necrosis 24 hours after angioplasty, and 1 after urgent bypass surgery). Mean (+/- standard deviation) fibrinogen levels were 355 +/- 73 mg/dl before urokinase infusion, and 361 +/- 70, twelve hours afterward. Three patients had local bleeding, but no transfusions were needed. It is concluded that intracoronary urokinase is a safe and effective adjunct to PTCA in patients with associated thrombi and may improve the success rate in angioplasty complicated by thrombus formation.

Absent left main coronary artery: angiographic findings in 83 patients with separate ostia of the left anterior descending and circumflex arteries at the left aortic sinus.

Among 20,332 adult patients who underwent consecutive cardiac catheterization and coronary arteriography, 83 (0.4%) were angiographically identified as having an absent left main coronary artery. The angiographic characteristics of this coronary anomaly include: (1) the presence of two well-separated coronary ostia at the left aortic sinus resulting in separate origin of the left anterior descending and circumflex arteries; (2) an increased incidence of left coronary dominance; (3) a higher (6%) than usual (0.5% to 1.5%) incidence of myocardial bridging; (4) lack of a high incidence of congenital heart anomalies; and (5) an incidence of atherosclerotic coronary artery disease similar to that of patients whose left main artery is intact. In 39% of the patients difficulties in selectively cannulating the separate ostium of the circumflex artery and adequately opacifying this vessel resulted in a need to change the diagnostic catheter size. Recognition of this coronary anomaly is needed to ensure accurate angiographic interpretation and is important for patients undergoing cardiac surgery to selectively perfuse these separate vessels during cardiopulmonary bypass.