Cold-season freeze frequency is a pervasive driver of subcontinental forest growth.

As northern latitudes experience rapid winter warming, there is an urgent need to assess the effect of varying winter conditions on tree growth and forest carbon sequestration potential. We examined tree growth responses to variability in cold-season (November­April) frequency of freeze days (FFD) over 1951 to 2018 using tree-ring data from 35,217 trees and 57 species at 4,375 sites distributed across Canada. We found that annual radial growth responses to FFD varied by species, with some commonalities across genera and clades. The growth of gymnosperms with late spring leaf-out strategies was negatively related to FFD; years with high FFD were most detrimental to the annual growth of Pinus banksiana, Pinus contorta, Larix lyalli, Abies amabilis, and Abies lasiocarpa. In contrast, the growth of angiosperms with early leaf-out strategies, namely, Populus tremuloides and Betula papyrifera, was better in the coldest years, and gymnosperms with intermediate leaf-out timing, such as widespread Picea mariana and Picea glauca, had no consistent relationship to FFD. Tree growth responses to FFD were further modulated by tree size, tree age, regional climate (i.e., mean cold-season temperature), and local site conditions. Overall, our results suggest that moderately warming winters may temporarily improve the growth of widespread pines and some high-elevation conifers in western Canada, whereas warming winters may be detrimental to the growth of widespread boreal angiosperms. Our findings also highlight the value of using species-specific climate-growth relationships to refine predictions of forest carbon dynamics.

Adding Tree Rings to North America's National Forest Inventories: An Essential Tool to Guide Drawdown of Atmospheric CO2.

Tree-ring time series provide long-term, annually resolved information on the growth of trees. When sampled in a systematic context, tree-ring data can be scaled to estimate the forest carbon capture and storage of landscapes, biomes, and-ultimately-the globe. A systematic effort to sample tree rings in national forest inventories would yield unprecedented temporal and spatial resolution of forest carbon dynamics and help resolve key scientific uncertainties, which we highlight in terms of evidence for forest greening (enhanced growth) versus browning (reduced growth, increased mortality). We describe jump-starting a tree-ring collection across the continent of North America, given the commitments of Canada, the United States, and Mexico to visit forest inventory plots, along with existing legacy collections. Failing to do so would be a missed opportunity to help chart an evidence-based path toward meeting national commitments to reduce net greenhouse gas emissions, urgently needed for climate stabilization and repair.

Positive and Negative Affect Is Related to Experiencing Chest Pain During Exercise-Induced Myocardial Ischemia.

OBJECTIVE: Silent myocardial ischemia is thought to be associated with worse cardiovascular outcomes due to a lack of perception of pain cues that initiate treatment seeking. Negative affect (NA) has been associated with increased pain reporting and positive affect (PA) with decreased pain reporting, but these psychological factors have not been examined within the context of myocardial ischemia. This study evaluated the associations between PA, NA, and chest pain reporting in patients with and without ischemia during exercise testing. METHODS: A total of 246 patients referred for myocardial perfusion single-photon emission computed tomography exercise stress testing completed the positive and negative affect schedule-expanded version, a measure of PA and NA. Presence of chest pain and myocardial ischemia were evaluated using standardized protocols. RESULTS: Logistic regression analyses revealed that for every 1-point increase in NA, there was a 13% higher chance for ischemic patients (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.02 to 1.26) and an 11% higher chance in nonischemic patients (OR = 1.11; 95% CI = 1.03 to 1.19) to report chest pain. A significant interaction of PA and NA on chest pain reporting (ß = 0.02; 95% CI = 0.002 to 0.031) was also observed; nonischemic patients with high NA and PA reported more chest pain (57%) versus patients with low NA and low PA (13%), with high NA and low PA (17%), and with high PA and low NA (7%). CONCLUSIONS: Patients who experience higher NA are more likely to report experiencing chest pain. In patients without ischemia, high NA and PA was also associated with a higher likelihood of reporting chest pain. Results suggest that high levels of PA as well as NA may increase the experience and/or reporting of chest pain.

Transmission of Lung Adenocarcinoma From a Single Donor in 2 Transplant Recipients: A Case Report With Literature Review.

Malignancies transmitted to recipients during solid organ transplants carry significant morbidity and mortality. We present 2 cases of adenocarcinoma of donor lung origin transmitted via liver and kidney transplant from a single donor. Both recipients developed metastatic adenocarcinoma of lung origin with p.L858R mutation in the epidermal growth factor receptor gene and a microsatellite signature of donor origin. Osimertinib was trialed in the liver recipient; however, it was discontinued because of hepatotoxicity and disease progression. Standard donor screening protocols limit malignancy transmission but do not include multicancer detection assays. As these technologies evolve, they may be implemented in donor screening.

The research on endothelial function in women and men at risk for cardiovascular disease (REWARD) study: methodology.

BACKGROUND: Endothelial function has been shown to be a highly sensitive marker for the overall cardiovascular risk of an individual. Furthermore, there is evidence of important sex differences in endothelial function that may underlie the differential presentation of cardiovascular disease (CVD) in women relative to men. As such, measuring endothelial function may have sex-specific prognostic value for the prediction of CVD events, thus improving risk stratification for the overall prediction of CVD in both men and women. The primary objective of this study is to assess the clinical utility of the forearm hyperaemic reactivity (FHR) test (a proxy measure of endothelial function) for the prediction of CVD events in men vs. women using a novel, noninvasive nuclear medicine -based approach. It is hypothesised that: 1) endothelial dysfunction will be a significant predictor of 5-year CVD events independent of baseline stress test results, clinical, demographic, and psychological variables in both men and women; and 2) endothelial dysfunction will be a better predictor of 5-year CVD events in women compared to men. METHODS/DESIGN: A total of 1972 patients (812 men and 1160 women) undergoing a dipyridamole stress testing were recruited. Medical history, CVD risk factors, health behaviours, psychological status, and gender identity were assessed via structured interview or self-report questionnaires at baseline. In addition, FHR was assessed, as well as levels of sex hormones via blood draw. Patients will be followed for 5 years to assess major CVD events (cardiac mortality, non-fatal MI, revascularization procedures, and cerebrovascular events). DISCUSSION: This is the first study to determine the extent and nature of any sex differences in the ability of endothelial function to predict CVD events. We believe the results of this study will provide data that will better inform the choice of diagnostic tests in men and women and bring the quality of risk stratification in women on par with that of men.

Association between clinical depression and endothelial function measured by forearm hyperemic reactivity.

OBJECTIVE: To assess associations between clinically significant depression (major depressive disorder [MDD] and minor depressive disorder [MiDD]) and endothelial function (EF), via forearm hyperemic reactivity (FHR), in patients referred for myocardial perfusion imaging. Studies have linked MDD to impaired EF, an early marker of coronary heart disease (CHD) and risk factor for cardiac events, in healthy, noncardiac patients, although no studies have assessed the MDD-EF association in patients with or at risk for CHD. METHODS: Depression was assessed, using the Primary Care Evaluation of Mental Disorders structured interview in 323 patients (n = 242 men; mean age = 59 years) with or at risk for CHD. FHR was assessed, using a dynamic nuclear imaging technique that measures the dilatory capability of the brachial artery during hyperemic challenge. The relative uptake ratio (RUR) of blood flow between hyperemic and nonhyperemic arms was used to measure FHR. RESULTS: Patients with MDD and MiDD had lower RURs (mean values = 3.31 and 3.34, respectively), indicating poorer EF than patients without depression (mean = 4.27) (F = 5.19, p < .01), irrespective of CHD status. All results were adjusted for covariates including sociodemographic, medical, biochemical, and physiological variables. CONCLUSIONS: Patients with clinical levels of depression had worse FHR than patients without depression, irrespective of CHD status and after adjusting for covariates. Data extend previous findings, suggesting that the link between clinical depression and worse CHD outcomes may be mediated by EF.

The role of mood disorders in exercise-induced cardiovascular reactivity.

OBJECTIVE: Increased cardiovascular (CV) reactivity has been associated with worse CV prognosis. Though mood disorders (MDs) have been associated with increased CV reactivity during behavioral stressors, the extent to which MDs and their interaction with coronary heart disease (CHD) influences exercise-induced CV reactivity has not been evaluated. METHODS: Five hundred twenty-six patients underwent nuclear exercise stress testing. Cardiovascular parameters were assessed at rest, every 2 minutes during exercise, and at peak exercise. MDs were measured using a structured psychiatric interview, the Primary Care Evaluation of Mental Disorders, and CHD was defined as having a history of myocardial infarction, revascularization, heart failure, and/or cerebrovascular event. RESULTS: CHD patients exhibited lower peak exercise heart rate (F = 9.40, p = .002) compared with patients without CHD. Submaximal data showed that patients with CHD had a slower rate of increase of heart rate (F = 4.29, p = .04) and diastolic blood pressure (F = 3.27, p = .04). There was an interaction of CHD and MDs, indicating that in patients with CHD, the rate of submaximal increase in systolic blood pressure (F = 3.08, p = .047) and rate-pressure product (F = 5.13, p = .006) was greater in patients with a MD compared with those without a MD. These differences were not observed in patients with no CHD. No other main or interaction effects of MDs and CHD were observed. CONCLUSION: Though MDs alone do not seem to be associated with higher levels of stress CV reactivity, their combination with CHD leads to increased submaximal exercise-induced CV reactivity. Prospective studies are needed to explore the causal relationship between these variables.

Health behaviors and endothelial function.

An unhealthy lifestyle, including excess caloric intake, lack of exercise, smoking, and excessive alcohol consumption, increases one's risk of developing cardiovascular disease (CVD). However, the exact mechanisms by which these behaviors influence the development and progression of CVD have yet to be determined. Endothelial function (EF) has been shown to be a potent predictor of CVD, yet the effects of health behaviors on EF are not clear. The literature assessing the role of four health behaviors, obesity (a proxy of excess caloric intake), smoking, physical inactivity, and alcohol consumption, on the development of endothelial dysfunction is reviewed. Potential mechanisms through which these behaviors may influence EF are discussed. Smoking, being overweight or obese, and physical inactivity are all associated with decreased EF. A direct causal relationship between these measures and EF is suggested by the fact that improvements in these behaviors leads to parallel improvements in EF. The influence of alcohol consumption is somewhat more contentious, with some studies indicating a dose-response relationship such that those with greater consumption have poor EF. However, other studies have shown that those who drink moderately have the best EF. Although there is a growing body of literature implicating poor health behaviors in the development of endothelial dysfunction, more work is needed to establish the exact mechanisms by which this occurs. To our knowledge, there are no studies that have assessed the impact of multiple health behaviors or the interaction of health behaviors on EF.

Health Locus of Control Is Associated With Physical Activity and Other Health Behaviors in Cardiac Patients.

PURPOSE: Physical inactivity, smoking, and excessive alcohol use are well-recognized modifiable risk factors for cardiovascular disease (CVD), yet uptake of strategies to mitigate these poor health behaviors varies widely among patients with cardiovascular disease. Part of this variation may be explained by health locus of control (HLOC), defined as the extent to which individuals believe their health is a consequence of their own actions, chance, or the influence of others (eg, physicians). METHODS: A total of 599 cardiac outpatients (30% female, 61.4 ± 9.4 y of age) completed the Multidimensional Health Locus of Control questionnaire and a structured health behavior questionnaire assessing physical activity, smoking, and alcohol use, at baseline and a 4-y follow-up. Relationships between health behaviors and HLOC were assessed cross-sectionally and longitudinally using general linear models and logistic regression models adjusting for medical and sociodemographic factors. RESULTS: Higher Internal HLOC was found to be associated with higher levels of leisure time physical activity (LTPA) (ß = .21, P = .0008), while lower Internal HLOC was associated with decreasing levels of alcohol consumption over time (ß = .26, P = .03). Increasing Chance HLOC was related to lower levels of leisure time physical activity (ß = -.15, P = .047) and increased likelihood of being a smoker (ß = .10, P = .01), and increasing physician HLOC was associated with decreased likelihood of being a smoker (ß = -.17, P = .01). CONCLUSIONS: Associations between HLOC and multiple health behaviors were observed in a large sample of cardiac outpatients. Results suggest that assessing and targeting HLOC beliefs of cardiac patients may be clinically relevant for behavior change in settings, such as in rehabilitation programs where behavior change is a goal.

Relationship between antidepressant therapy and risk for cardiovascular events in patients with and without cardiovascular disease.

OBJECTIVE: The American Heart Association has endorsed depression as a cardiac risk factor and recommends screening as part of routine practice. This has been met with controversy due to inconsistencies in the data linking depression treatment to better cardiovascular outcomes. Our objective was to prospectively assess the association between depression treatment (defined as being prescribed antidepressant medication) and major adverse cardiovascular events (MACE) in patients referred for exercise stress tests. METHOD: Two thousand three hundred eighty-five consecutive patients presenting for myocardial perfusion exercise stress tests underwent a sociodemographic, medical, and psychiatric interview (Primary Care Evaluation of Mental Disorders [PRIME-MD]) and completed the Beck Depression Inventory (BDI). History of cardiovascular disease (CVD) and antidepressant use was self-reported and verified via chart review. Participants followed over an 8.8-year follow up, and information regarding MACE incidence (including cardiac mortality, nonfatal myocardial infarction, revascularization procedures, cerebrovascular events) was obtained from provincial administrative databases. RESULTS: 8% (n = 190) of the sample were taking antidepressants at baseline, 41% (n = 916) had a history of CVD, and 38.7% (n = 921) had depression according to the PRIME-MD or BDI. Antidepressant treatment was associated with a 30% reduced risk of MACE (Hazard ratio [HR] = 0.697; 95% confidence interval [CI] = [0.504, 0.964]; p = .029). A 46% reduction in risk was associated with antidepressant treatment among those without CVD (HR = 0.542; 95% CI [0.299, 0.981]; p = .043). In depressed patients, a 33% reduction in risk of MACE associated with antidepressant use was seen (adjusted HR = 0.674; 95% CI [0.440, 1.033]; p = .07). CONCLUSIONS: Antidepressants may be cardio-protective among patients presenting for stress testing independent of risk factors including CVD and depression. Results support treating depression with antidepressants in this population to reduce risk of MACE. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Angina symptoms in men and women with stable coronary artery disease and evidence of exercise-induced myocardial perfusion defects.

BACKGROUND: To examine sex differences in pain and associated symptoms in patients with exercise-related ischemia, as well as the independence of these findings from other clinical factors. METHODS: Prospective study of 482 women and 425 men (mean age 58 years) undergoing exercise stress testing with myocardial perfusion imaging (MPI). Analyses were performed on 38 women and 94 men with both angina and MPI evidence of ischemia during exercise. MEASURES: Chest pain localization, extension, intensity, quality, and presence of various non-pain-related symptoms. RESULTS: Women rated their pain as more intense, used different words to describe it, and reported more non-pain-related symptoms than men (P < .05). They experienced pain and other sensations in the neck area more frequently (P < .05). Most of these differences remained after controlling for clinical or psychological variables, with the exception of pain intensity measures. CONCLUSIONS: Sex differences in the experience of symptoms associated with MPI evidence of myocardial ischemia may complicate timely and accurate diagnosis of ischemia in women.

Do Women With Anxiety or Depression Have Higher Rates of Myocardial Ischemia During Exercise Testing Than Men?

BACKGROUND: Women diagnosed with coronary artery disease (CAD) typically experience worse outcomes relative to men, possibly through diagnosis and treatment delays. Reasons for these delays may be influenced by mood and anxiety disorders, which are more prevalent in women and have symptoms (eg, palpitations and fatigue) that may be confounded with CAD. Our study examined sex differences in the association between mood and anxiety disorders and myocardial ischemia in patients with and without a CAD history presenting for exercise stress tests. METHODS AND RESULTS: A total of 2342 patients (women n=760) completed a single photon emission computed tomographic exercise stress test (standard Bruce Protocol) and underwent a psychiatric interview (The Primary Care Evaluation of Mental Disorders) to assess mood and anxiety disorders. Ischemia was assessed using single photon emission computed tomography, with odds ratio used to calculate the effect of sex and mood/anxiety on the presence of ischemia during stress testing by CAD history in a stratified analyses, adjusted for relevant covariates. There was a sex by anxiety interaction with ischemia in those without a CAD history (P=0.015): women with anxiety were more likely to exhibit ischemia during exercise than women without anxiety (odds ratio, 1.75; 95% confidence interval, 1.05-2.89). No significant effects were observed for men nor mood. CONCLUSIONS: Women with anxiety and no CAD history had higher rates of ischemia than women without anxiety. Results suggest that anxiety symptoms, many of which overlap with those of CAD, might mask CAD symptoms among women (but not men) and contribute to referral and diagnostic delays. Further research is needed to confirm this hypothesis.

Exercise Lowers Plasma Angiopoietin-Like 2 in Men with Post-Acute Coronary Syndrome.

Pro-inflammatory angiopoietin-like 2 (angptl2) promotes endothelial dysfunction in mice and circulating angptl2 is higher in patients with cardiovascular diseases. We previously reported that a single bout of physical exercise was able to reduce angptl2 levels in coronary patients. We hypothesized that chronic exercise would reduce angptl2 in patients with post-acute coronary syndrome (ACS) and endothelial dysfunction. Post-ACS patients (n = 40, 10 women) were enrolled in a 3-month exercise-based prevention program. Plasma angptl2, hs-CRP, and endothelial function assessed by scintigraphic forearm blood flow, were measured before and at the end of the study. Exercise increased VO2peak by 10% (p<0.05), but did not significantly affect endothelial function, in both men and women. In contrast, exercise reduced angptl2 levels only in men (-26±7%, p<0.05), but unexpectedly not in women (+30±16%), despite similar initial levels in both groups. Exercise reduced hs-CRP levels in men but not in women. In men, levels of angptl2, but not of hs-CRP, reached at the end of the training program were negatively correlated with VO2peak (r = -0.462, p = 0.012) and with endothelial function (r = -0.419, p = 0.033) measured at baseline: better initial cardiopulmonary fitness and endothelial function correlated with lower angptl2 levels after exercise. Pre-exercise angptl2 levels were lower if left ventricular ejection time was long (p<0.05) and the drop in angptl2 induced by exercise was greater if the cardiac output was high (p<0.05). In conclusion, in post-ACS men, angptl2 levels are sensitive to chronic exercise training. Low circulating angptl2 reached after training may reflect good endothelial and cardiopulmonary functions.

Two-year angiographic follow-up of intracoronary Sr90 therapy for restenosis prevention after balloon angioplasty.

BACKGROUND: Postcoronary angioplasty vascular brachytherapy (VBT) has emerged as a successful intervention for restenosis prevention in some clinical scenarios. Longer-term follow-up after VBT in de novo nonstented lesions has not been reported. METHODS AND RESULTS: Thirty patients treated with post-percutaneous transluminal coronary angioplasty (PTCA) VBT with Sr90 underwent clinical and angiographic follow-up at 6 and 24 months. Specific vessel segment quantitative coronary angiographic analyses were performed to identify radiation edge effects. Nineteen patients who had not undergone index procedure stenting or target vessel revascularization (TVR) over the 2-year period were analyzed separately. Of the 30 patients, 3 underwent TVR by 6-month follow-up. An additional 4 patients required TVR between 6 and 24 months. In the total cohort of 26 patients undergoing angiographic follow-up at 6 and 24 months, an increase in minimal lumen diameter of the initial target segment was noted at 6 months compared with postprocedure analysis (2.31+/-0.48 versus 2.04+/-0.43 mm, P<0.05). At 24 months, this was no longer significant (2.19+/-0.61 mm). In the proximal segments of the entire cohort and the nonintervened subgroup, the principal late loss occurred over the first 6 months with no additional late loss at 2-year follow-up. The distal segments remained stable over the entire follow-up period. CONCLUSIONS: Although some late failures of post-PTCA VBT are seen between 6 and 24 months, most treated vessels remain stable with no late loss or additional luminal increase beyond the 6-month period. This suggests that late aneurysm formation and significant late edge restenosis are unlikely in VBT after PTCA of de novo lesions for up to 2 years.

Beta-radiation for the creation of linear lesions in the canine atrium.

BACKGROUND: Creating linear lesions is important for the treatment of arrhythmias such as atrial flutter and fibrillation. Making these lesions with standard radiofrequency catheters can be difficult and may result in charring and thrombosis. The purpose of this study was to evaluate beta-radiation as a novel energy source for creating linear myocardial lesions. METHODS AND RESULTS: Eight dogs with intact conduction across the cavotricuspid isthmus were studied. The isthmus was irradiated (25 to 50 Gy) with strontium/yttrium-90 delivered via a deflectable 7F catheter (Novoste Corporation). There were no immediate effects, but bidirectional conduction block developed during follow-up studies in 7 of 8 dogs. The dog without conduction block received 25 Gy. After the animals were euthanized, histology revealed transmural, linear areas of fibrosis without any thrombus. CONCLUSIONS: Beta-radiation can safely and effectively create linear lesions that are contiguous and nonthrombogenic. This energy source may become an interesting adjunct to radiofrequency for the treatment of atrial flutter and fibrillation.

Quantitative hyperemic reactivity in opposed limbs during myocardial perfusion imaging: a new marker of coronary artery disease.

OBJECTIVES: We sought to evaluate the feasibility and validity of a new method to quantify the hyperemic response of the forearms that can be incorporated into a rest myocardial perfusion protocol. BACKGROUND: Evaluation of the hyperemic response could provide useful clinical information in the detection and risk stratification of atherosclerotic vascular disease. METHODS: Patients with proven coronary artery disease (CAD) (n = 46) were compared with low-risk subjects without such evidence (n = 47). A regular dose of Myoview was injected after 5 min of right arm ischemia. Three dimensionless parametric ratios (right/left) were derived from the analysis of activity-time curves of the hyperemic right forearm and that of the contralateral left forearm. RESULTS: The maximal ingress upslope ratio was 40% lower in the CAD group (3.0 +/- 0.2 vs. 4.2 +/- 0.3, p < 0.0005), and the integral to peak ratio was also lower (23 +/- 4 vs. 52 +/- 11, p < 0.01), whereas the peak activity ratio was nonsignificantly lower (3.0 +/- 0.3 vs. 3.8 +/- 0.3, p = 0.07). Using a value of 3.55 for the maximal upslope ratio, this approach could predict the presence of CAD with a sensitivity of 0.70 and a specificity of 0.60. CONCLUSIONS: This simple and noninvasive method is feasible and can discriminate between patients with known CAD and those at low risk of atherosclerosis. Refinements of this approach and its inclusion in larger clinical trials are needed to determine whether it could provide additional value to myocardial scintigraphic imaging.

A pilot study: the Noninvasive Surface Cooling Thermoregulatory System for Mild Hypothermia Induction in Acute Myocardial Infarction (the NICAMI Study).

BACKGROUND: Hypothermia reduces metabolic demands, limits reperfusion injury, and helps salvage the injured myocardium during ST-elevation myocardial infarction (STEMI). The aim of this study was to assess early induction of noninvasive mild hypothermia in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention (PCI). METHODS: This was a safety and feasibility study of the Medivance Arctic Sun noninvasive thermoregulatory system (Medivance Inc, Louisville, Colo), used as adjunctive therapy in patients with first-time STEMI. Cooling was initiated by circulating chilled water through the Arctic Sun Energy Transfer Pads placed on the patient before primary PCI. Target temperature was 34.5 degrees C, maintained during 3 hours. Shivering was controlled with intravenous meperidine, and meperidine-related nausea was prevented with intravenous ondansetron. RESULTS: Nine patients underwent successful noninvasive surface cooling. All patients were Killip class I with a mean age of 62 years (8/9 males). Successful primary stenting was performed in all patients with glycoprotein inhibitors administered in 6 of 9 cases. Mean cooling time from induction to target temperature was 79 minutes (49 minutes in the last 4 enrolled cases). Mean total cooling duration was 267 minutes. Mean peak troponin T was 5.81 microg/L. Final TIMI flow grade 3 and final TIMI perfusion grade 3 were achieved in 9 of 9 patients and in 3 of 9 patients, respectively. Mean infarct size (by Myoview single photon emission computed tomography scans) was 23%. No hemodynamic or arrhythmic instability were documented. CONCLUSION: Mild hypothermia can be safely induced with noninvasive surface cooling in patients with STEMI undergoing primary PCI, allowing earlier myocardial protection before mechanical reperfusion therapy.

Myocardial perfusion study of panic attacks in patients with coronary artery disease.

Panic disorder (PD) and panic-like anxiety have been associated with an increased risk of cardiovascular death. No study has specifically examined the association between panic attacks and ischemia in patients who have coronary artery disease (CAD). We hypothesized that panic attacks would induce myocardial perfusion defects in patients who have CAD and PD. Sixty-five patients who had CAD and positive results with nuclear exercise stress testing (35 with PD and 30 without PD served as controls) underwent a well-established panic challenge test (1 vital capacity inhalation of a gas mixture containing 35% carbon dioxide and 65% oxygen) and were injected with technetium-99m sestamibi at inhalation. Single-photon emission computed tomography was used to assess per-panic challenge perfusion defects, and heart rate, blood pressure, and 12-lead electrocardiogram were continuously measured during the procedure. Patients were not withdrawn from their cardiac medications. Patients who had PD were significantly younger than the controls; otherwise groups did not differ with respect to gender, cardiac medications, nuclear exercise test results, and baseline heart rate and blood pressure. Seventy-four percent of patients (26 of 35) who had PD had a panic attack at inhalation versus 6.7% of controls (2 of 30, p <0.001). As hypothesized, patients who had PD and demonstrated a panic attack were more likely to develop a reversible myocardial perfusion defect than were controls who did not have an attack (80.9% vs 46.4% p = 0.009). Thus, despite being on their cardiac medications, panic attacks preferentially induced significant perfusion defects in patients who had CAD and PD. In conclusion, panic attacks in patients who have CAD appear to be bad for the heart.

Synthetic self-propelled nanorotors.

Self-powered completely synthetic nanorotors have been prepared from barcoded gold-nickel nanorods having the gold end anchored to the surface of a silicon wafer; constant velocity circular movements are observed when hydrogen peroxide fuel is catalytically decomposed to oxygen at the unattached nickel end of the nanorod.