Pulmonary transit time from contrast echocardiography and cardiac magnetic resonance imaging: Comparison between modalities and the impact of region of interest characteristics.

INTRODUCTION: The degree of correlation of pulmonary transit time (PTT) between contrast echocardiography and cardiac magnetic resonance imaging (MRI) across the spectrum of cardiac disease has not been quantified. In addition, the degree to which PTT estimates are affected by variation in location and size of regions of interest (ROI) is unknown. METHODS: Pulmonary transit time was obtained using an inflection point technique from individuals that underwent contrast echocardiography and cardiac MRI. Right ventricular, left atrial, and left ventricular ROIs were evaluated, and two sizes for each ROI were used. The Spearman correlation coefficient and Bland-Altman analysis were used for comparisons between modalities. Bland-Altman plots were also used to measure the impact of ROI size and location on transit times. RESULTS: Fourteen participants (age: 27-64 years; LV ejection fraction: 30%-60%) underwent both studies a median of 1 week apart. The correlation between modalities was significant for PTT (r = 0.65; P = 0.01) and normalized PTT (r = 0.80; P = 0.001). Cardiac MRI yielded transit times consistently higher than contrast echocardiography (bias ~ 1.4 seconds), but the discordance was not dependent on transit time magnitude. Low bias was observed for comparisons of ROI size and location (<0.5 seconds). CONCLUSIONS: Contrast echocardiography underestimates transit time measurements obtained by cardiac MRI, although the discrepancy was systematic and may have been contributed to by the interval between imaging studies. ROI location and size did not impact transit time values, suggesting that ROIs could be placed without intensive training, a step toward incorporation of real-time PTT measurement into echocardiographic laboratory workflow.

Effects of Advanced Cardiac Procedure Simulator Training on Learning and Performance in Cardiovascular Medicine Fellows.

BACKGROUND: Simulation-based training has been used in medical training environments to facilitate the learning of surgical and minimally invasive techniques. We hypothesized that integration of a procedural simulation curriculum into a cardiology fellowship program may be educationally beneficial. METHODS: We conducted an 18-month prospective study of cardiology trainees at Vanderbilt University Medical Center. Two consecutive classes of first-year fellows (n = 17) underwent a teaching protocol facilitated by simulated cases and equipment. We performed knowledge and skills evaluations for 3 procedures (transvenous pacing [TVP] wire, intra-aortic balloon pump [IABP], and pericardiocentesis [PC]). The index class of fellows was reevaluated at 18 months postintervention to measure retention. Using nonparametric statistical tests, we compared assessments of the intervention group, at the time of intervention and 18 months, with those of third-year fellows (n = 7) who did not receive simulator-based training. RESULTS: Compared with controls, the intervention cohort had higher scores on the postsimulator written assessment, TVP skills assessment, and IABP skills assessment (P = .04, .007, and .02, respectively). However, there was no statistically significant difference in scores on the PC skills assessment between intervention and control groups (P = .08). Skills assessment scores for the intervention group remained higher than the controls at 18 months (P = .01, .004, and .002 for TVP, IABP, and PC, respectively). Participation rate was 100% (24/24). CONCLUSIONS: Procedural simulation training may be an effective tool to enhance the acquisition of knowledge and technical skills for cardiology trainees. Future studies may address methods to improve performance retention over time.

Photodermatitis for the Allergist.

PURPOSE OF REVIEW: The photodermatoses represent a group of disorders of sensitivity to light that continue to pose difficulties in diagnosis and management. Photodermatoses are of interest to allergists because many photosensitive skin disorders have immunologic underpinnings, and patients often present to clinic complaining of "allergy" to the sun. We provide a concise reference for allergists on the clinical recognition and management of photodermatitis. RECENT FINDINGS: New developments in the understanding of immunomodulatory effects of light have demonstrated normally immunosuppressive responses in the skin to light exposure, and a blunted immunosuppressive response in the pathogenesis of many photodermatoses. Vitamin D plays an important role in immunomodulation and itself may be affected by photodermatoses due to the impact of photoprotective treatment strategies on circulating vitamin D levels. The elucidation of the immunological basis of many photodermatoses may provide guidance for developing new treatment modalities. Further research is necessary to determine the optimal management of vitamin D metabolism in patients with photodermatoses.

Acute Mitral Regurgitation After Removal of an Impella Device.

Acute mitral regurgitation is a very rare complication of an Impella device. We report a case of a 52-year-old man who had an Impella CP device placed for cardiogenic shock and developed acute mitral regurgitation after removal of the Impella. This was managed with the placement of TandemHeart device.

Clostridium difficile infection in dialysis patients.

Clostridium difficile infection (CDI) is the most common cause of nosocomial diarrhea. Patients with end-stage renal disease (ESRD) may be at increased risk for CDI. Patients with ESRD with CDI have increased mortality, longer length of stay, and higher costs. The present studies extend these observations and address associated comorbidities, incidence of recurrence, and risk factors for mortality. We queried the United States Renal Data System (USRDS) for patients with ESRD diagnosed with CDI, and assessed for the incidence of infection, comorbidities, and mortality. The records of 419,875 incident dialysis patients from 2005 to 2008 were reviewed. 4.25% had a diagnosis of a first CDI. In the majority of patients with CDI positive, a hospitalization or ICU stay was documented within 90 days prior to the diagnosis of CDI. The greatest adjusted relative risk (aRR) of CDI was present in patients with HIV (aRR 2.68), age ≥65 years (aRR 1.76), and bacteremia (aRR 1.74). The adjusted HR (aHR) for death was 1.80 in patients with CDI. The comorbidities demonstrating the greatest risk for death in dialysis patients with CDI included age ≥65 years and cirrhosis (aHR 2.28 and 1.76, respectively). Recurrent CDI occurred in 23.6%, was more common in Caucasians, and in those who were older. CDI is a common occurrence in patients with ESRD, with elderly patients, patients with HIV positive, and bacteremic patients at highest risk for infection. Patients with CDI had nearly a twofold increased risk of death.

Right ventricular afterload sensitivity dramatically increases after left ventricular assist device implantation: A multi-center hemodynamic analysis.

BACKGROUND: Right ventricular (RV) failure is a source of morbidity and mortality after left ventricular assist device (LVAD) implantation. In this study we sought to define hemodynamic changes in afterload and RV adaptation to afterload both early after implantation and with prolonged LVAD support. METHODS: We reviewed right heart catheterization (RHC) data from participants who underwent continuous-flow LVAD implantation at our institutions (n = 244), excluding those on inotropic or vasopressor agents, pulmonary vasodilators or additional mechanical support at any RHC assessment. Hemodynamic data were assessed at 5 time intervals: (1) pre-LVAD (within 6 months); (2) early post-LVAD (0 to 6 months); (3) 7 to 12 months; (4) 13 to 18 months; and (5) very late post-LVAD (18 to 36 months). RESULTS: Sixty participants met the inclusion criteria. All measures of right ventricular load (effective arterial elastance, pulmonary vascular compliance and pulmonary vascular resistance) improved between the pre- and early post-LVAD time periods. Despite decreasing load and pulmonary artery wedge pressure (PAWP), RAP remained unchanged and the RAP:PAWP ratio worsened early post-LVAD (0.44 [0.38, 0.63] vs 0.77 [0.59, 1.0], p < 0.001), suggesting a worsening of RV adaptation to load. With continued LVAD support, both RV load and RAP:PAWP decreased in a steep, linear and dependent manner. CONCLUSIONS: Despite reducing RV load, LVAD implantation leads to worsened RV adaptation. With continued LVAD support, both RV afterload and RV adaptation improve, and their relationship remains constant over time post-LVAD. These findings suggest the RV afterload sensitivity increases after LVAD implantation, which has major clinical implications for patients struggling with RV failure.

Adverse neurologic events in patients bridged with long-term mechanical circulatory support: A device-specific comparative analysis.

BACKGROUND: Neurologic complications are among the principal causes of morbidity and mortality after continuous-flow left ventricular assist device (CF-LVAD) implantation. The aim of this study was to describe a focused "real-world" multicenter comparison of neurologic outcomes between HeartMate II (HMII) and HeartWare HVAD CF-LVAD recipients. METHODS: Between March 2009 and October 2014, 497 patients underwent primary CF-LVAD implantation as a bridge to transplantation at centers included in the Mechanical Circulatory Support Research Network; 314 patients (63%) received HMII, and 183 patients (37%) received HVAD. Ischemic cerebrovascular accident, hemorrhagic cerebrovascular accident, and transient ischemic attack were the neurologic outcomes assessed. RESULTS: Median follow-up time for HMII recipients was 0.95 years (0.48, 1.85, range) and for HVAD recipients was 0.44 years (0.19, 0.97, range) (p < 0.001). HMII recipients had significantly fewer neurologic events per patient year for ischemic cerebrovascular accident (0.071) and transient ischemic attack (0.012) compared with HVAD recipients (0.157 and 0.072, respectively). Univariate analysis showed that 51 HMII recipients (16%) had any neurologic event, whereas 34 HVAD recipients (19%) had any neurologic event (p = 0.504). After adjusting for pre-specified covariates (device type, age, sex, atrial fibrillation, diabetes, and Interagency Registry for Mechanically Assisted Circulatory Support profile), multivariable analysis showed only advanced age was able to predict neurologic events (p = 0.02). Neurologic events were comparable between HMII and HVAD recipients after multivariable analysis. CONCLUSIONS: CF-LVAD placement incurs a low but significant risk of neurologic complications in patients receiving CF-LVADs as a bridge to transplantation. Advancing age is a risk factor for any adverse neurologic outcome. This multicenter analysis demonstrated comparable hazard of adverse neurologic events among patients implanted with HMII or HVAD.

Kidney dysfunction and left ventricular assist device support: a comprehensive perioperative review.

Left ventricular assist devices (LVADs) are used increasingly as a bridge to transplantation or as destination therapy in end-stage heart failure patients who do not respond to optimal medical therapy. Many of these patients have end-organ dysfunction, including advanced kidney dysfunction, before and after LVAD implantation. Kidney dysfunction is a marker of adverse outcomes, such as increased morbidity and mortality. This review discusses kidney dysfunction and associated management strategies during the dynamic perioperative time period of LVAD implantation. Furthermore, we suggest potential future research directions to better understand the complex relationship between renal pathophysiology and mechanical circulatory support.

Eosinophilic myocarditis-an unusual cause of left ventricular hypertrophy.

Eosinophilic myocarditis is a rare condition in which inflammation of the heart results in an infiltrative cardiomyopathy that is often difficult to diagnose in the acute setting. It sometimes presents as left ventricular hypertrophy. The authors present a case of a 79-year-old woman with a history of Non-Hodgkin's lymphoma who presented with acute heart failure with marked left ventricular hypertrophy. Echocardiography demonstrated abnormalities consistent with an infiltrative cardiomyopathy, and endomyocardial biopsy showed findings consistent with eosinophilic myocarditis. The patient was managed with diuresis and glucocorticoid therapy, and within 4 weeks of her admission, her clinical status had improved and her echocardiogram normalized. The prompt diagnosis and treatment of this patient's myocarditis likely resulted in her favorable outcome. This illustrates the need for a broad consideration of all the potential causes of hypertrophy and the necessary diagnostic strategies and therapeutic options.

Non-invasive management of vasovagal syncope.

Vasovagal syncope (VVS) is a common disorder of the autonomic nervous system. While recurrent syncope can cause very impaired quality of life, the spells are not generally life-threatening. Both non-pharmacological and pharmacological approaches can be used to treat patients. Conservative management with education, exercise and physical maneuvers, and aggressive volume repletion is adequate for controlling symptoms in most patients. Unfortunately, a minority of patients will continue to have recurrent syncope despite conservative therapy, and they may require medications. These could include vasopressor agents, beta-blockers, or neurohormonal agents. Some patients may require more aggressive device based therapy with pacemakers or radiofrequency ablation, which are emerging therapies for VVS. This paper will review non-procedure based treatments for VVS.

Ongoing clinical trials for Vasovagal Syncope: where are we in 2014?

Vasovagal Syncope (VVS) can lead to a markedly diminished quality of life for some patients. While there are many treatments for this condition including physical, mechanical, pharmacologic, and device-based control of heart rate, there are few that have been shown to be effective in randomized clinical trials. In our local experience, we have achieved significant improvement in symptom frequency and quality of life using algorithms based on the data available and on clinical acumen for the majority of patients with VVS. Despite this, there are still many patients who suffer from treatment refractory VVS. Fortunately, there are a number of ongoing clinical trials that are likely to add to our knowledge. Ongoing clinical trials are reviewed to examine new treatment methods for VVS that were listed on public trial registries as of April 15, 2014. Data from these trials should inform future strategies in the care of patients with VVS.

Medical therapy and physical maneuvers in the treatment of the vasovagal syncope and orthostatic hypotension.

Patients with vasovagal syncope and neurogenic orthostatic hypotension can both present with pre-syncope and syncope resulting from systemic hypotension. While not directly responsible for increased mortality, both of these conditions can have a tremendous deleterious impact on the daily lives of patients. This negative impact can take the form of both physical symptoms and injury, but also a psychological impact from living in fear of the next syncopal episode. Despite these similarities, these are different disorders with fixed damage to the autonomic nerves in neurogenic orthostatic hypotension, as opposed to a transient reflex hypotension in "neurally mediated" vasovagal syncope. The treatment approaches for both disorders are parallel. The first step is to educate the patient about the pathophysiology and prognosis of their disorder. Next, offending medications should be withdrawn when possible. Non-pharmacological therapies and maneuvers can be used, both in an effort to prevent the symptoms and to prevent syncope at the onset of presyncope. This is all that is required in many patients with vasovagal syncope. If needed, pharmacological options are also available for both vasovagal syncope and neurogenic orthostatic hypotension, many of which are focused on blood volume expansion, increasing cardiac venous return, or pressor agents to increase vascular tone. There is a paucity of high-quality clinical trial data to support the use of these pharmacological agents. We aim to review the literature on these different therapy choices and to give recommendations on tailored approaches to the treatment of these conditions.

Desmopressin acutely decreases tachycardia and improves symptoms in the postural tachycardia syndrome.

BACKGROUND: Postural tachycardia syndrome (POTS) induces disabling chronic orthostatic intolerance with an excessive increase in heart rate on standing, and many patients with POTS have low blood volume. Increasing blood volume is a promising approach to this problem. OBJECTIVE: To test the hypothesis that desmopressin (DDAVP) will attenuate the tachycardia and improve symptom burden in patients with POTS. METHODS: In this protocol, patients with POTS (n = 30) underwent acute drug trials with DDAVP 0.2 mg orally and placebo, on separate mornings, in a randomized crossover design. Blood pressure, heart rate, and symptoms were assessed while seated and after standing for up to 10 minutes prior to and hourly for 4 hours following study drug. RESULTS: The standing heart rate was significantly lower following DDAVP than placebo (101.9 ± 14.5 beats/min vs 109.2 ± 17.4 beats/min; P <.001). Standing blood pressure was not affected (P = .28). The symptom burden improved with DDAVP (from a score of 18 ± 18 arbitrary units [AU] to 13 ± 15 AU at 2 hours) compared with placebo (from 18 ± 17 AU to 19 ± 16 AU; P = .010). CONCLUSIONS: Oral DDAVP significantly attenuated tachycardia and improved symptoms in POTS. The safety profile of this approach would need to be examined before it can be recommended for routine treatment of these patients.

Surgical approaches for the prevention and treatment of type 2 diabetes mellitus.

Lifestyle modifications and pharmacologic therapy have been the mainstays of treatment for patients with type 2 diabetes mellitus. Bariatric surgery, originally designed as a weight loss treatment, has been proven to ameliorate and even cure diabetes. The significant improvement in glycemic control found after bariatric surgery in patients with diabetes often precedes major weight loss. Therefore, a weight-independent mechanism has been thought to initiate this amelioration in glucose control. Reviews of the recent literature question the goal of bariatric surgery, not only to treat obesity through restriction and malabsorption, but also as a possible treatment for diabetes regardless of the degree of obesity. Procedures such as Roux-en-Y gastric bypass, adjustable gastric banding, and biliopancreatic diversion have proven to be extremely effective in controlling diabetes mellitus. Mechanisms explaining the effectiveness of weight reduction surgery include effects on incretins, ghrelin secretion, and insulin sensitivity. Some centers have been performing gastric bypass surgeries on patients with a lower body mass index than that recommended by current NIH guidelines. New considerations for recommending bypass surgery are warranted as the indications for antiobesity surgeries grow to encompass both the treatment and cure of diabetes.