Interatrial pressure gradients during simulated obstructive sleep apnea: a catheter-based study.

OBJECTIVES: We set to measure the interatrial pressure gradient during simulated obstructive sleep apnea (OSA). BACKGROUND: OSA occurs when a sleeping patient attempts to inhale against an obstructed airway. How this event affects the interatrial pressure gradient has not been defined. We hypothesized that simulated OSA in a conscious subject (Mueller maneuver [MM], inspiration against obstruction) would promote increased right-to-left pressure gradient, and then the substrate for right-to-left atrial shunting. METHODS: Selected patients underwent simultaneous measurement of airway and atrial pressures (both left and right atrium [LA, RA]) using high-fidelity micromanometry at rest, during MM, and during VM, during right heart catheterization. RESULTS: Ten patients (age 55 ± 11 years, two women) were successfully studied. During the onset of MM, RA pressure transiently but consistently exceeded LA pressure in response to the steep decline in intrathoracic pressure (maximum RA-LA pressure gradient increased from 0.1 ± 1.4 mm Hg at baseline to 7.0 ± 4.3 mm Hg during MM, P < 0.001). The maximum right-to-left atrial pressure gradient during Mueller maneuver was higher than that achieved during the Valsalva maneuver release (P < 0.007). CONCLUSIONS: The onset of MM increased right-to-left pressure gradient across the atrial septum, likely as a result of greater blood return to the RA from extrathoracic veins. The RA-LA pressure gradient achieved during MM was greater than that observed during VM. These findings delineate the hemodynamic substrate for right to left shunting during OSA.

Cardiac device complications in the cognitively impaired.

BACKGROUND: Patients with preexisting mild cognitive impairment or dementia may be at increased risk for developing cardiac device complications due to an impaired ability to follow postimplant care instructions. We sought to determine whether rates of infection, lead dislodgement, or appropriate or inappropriate implantable cardioverter defibrillator (ICD) shocks are increased in this population. METHODS: Medical charts of 561 patients with mild cognitive impairment or dementia who underwent pacemaker (PM) or ICD implantation between January 2002 and October 2009 at Mayo Clinic were identified. A total of 134 patients who were diagnosed with cognitive impairment or dementia before device implantation or within 1 year of implantation were compared with 134 matched controls. Information was collected on patient characteristics, comorbid medical conditions, ejection fraction, complications, device type, device therapy, and mortality. Device information was prospectively entered into a database and retrospectively reviewed. RESULTS: Of the 134 patients with mild cognitive impairment and dementia, 99 underwent PM implantation and 35 underwent ICD implantation. Compared to controls, there was no difference in patient characteristics, ejection fraction, or comorbidities except for diabetes, which was more prevalent in the cognitively impaired and demented group (18.7% vs 30.6%, P = 0.02). There was no difference in device therapy and complications (14.4% vs 5.8%, P = 0.268). However, there was a decreased survival in patients with cognitive impairment and dementia when compared to the control group (42% vs 67% at 5 years, P = 0.007). CONCLUSION: Patients with cognitive impairment and standard device indications are not at increased risk for device complications and therapy but their survival is much lower than in matched controls. The cause of this lower survival is unknown but may be related to the underlying neurological disease. Presence of cognitive impairment should therefore be considered when contemplating implantation of a cardiac device.

Novel functional risk factors for the prediction of cardiovascular events in vulnerable patients following acute coronary syndrome.

Over the years there has been considerable improvement in the clinical outcomes of patients treated for acute coronary syndrome (ACS). Despite a significant reduction in acute mortality, a large percentage of patients post ACS continue to experience adverse cardiovascular (CV) events, with high long-term mortality rates and overall suboptimal medical management. Long-term risk prediction tools rely on traditional CV risk factors and are developed and validated in specific populations. Established CV risk factors, however, only explain half or fewer of CV events. These risk models may thus not be optimal in determining individual risk for long-term adverse outcomes or in helping to identify individual patients who do not respond to therapy. Identifying the specific plaque characteristics associated with increased likelihood for thrombotic complications and rapid progression has led to the concept of the vulnerable plaque. Recently, "vulnerable myocardium" (ie, myocardium that is prone to myocardial ischemia and fatal arrhythmia) has been shown to play an important role in outcome. Both vulnerable plaque and vulnerable myocardium are associated with functional vascular abnormalities, such as endothelial dysfunction, which are considered a key event in the initiation, progression and complications of coronary artery disease. Endothelial dysfunction may serve as an underlying unifying mechanism that would independently predict long-term outcome in patients with ACS undergoing revascularization.

Percutaneous closure of congenital coronary artery fistulae: results and angiographic follow-up.

OBJECTIVES: This study sought to assess clinical and angiographic outcomes in a series of 29 patients who underwent transcatheter closure of coronary artery fistulae (CAF). BACKGROUND: Transcatheter closure of CAF has become an alternative to surgical closure, but the reported experience is relatively limited. METHODS: Medical records of all patients with CAF who underwent transcatheter closure at the Mayo Clinic, Rochester, Minnesota, between 1997 and 2010, were reviewed. Patients with other complex cardiac lesions and those requiring surgery were excluded. RESULTS: Twenty-nine patients with CAF underwent 36 transcatheter closure procedures. The most were women (55%), and the median age at the time of transcatheter closure was 49 years. Twenty-three patients had a single CAF. The most common presenting symptom was chest pain (52%). Thirty devices were deployed antegrade into 1 or more arterial feeders, 3 using an arteriovenous wire loop and 3 retrograde at the fistulous connection. Successful closure occurred immediately in all patients with no residual flow in 89% and with trivial flow in 11%. Four complications occurred including 2 device migrations, 1 coronary spasm, and 1 coronary thrombosis. A follow-up angiogram was obtained in 18 (62%) patients with a median time to follow-up angiography of 1.5 years. Ten patients (56%) of the 18 patients with follow-up angiography had no recanalization of embolized vessel; 4 patients (22%) had trivial recanalization, and 4 patients (22%) had large recanalization. A repeat closure procedure was performed in all 4 patients of the latter. CONCLUSIONS: Transcatheter closure of CAF is feasible and should be considered in carefully selected patients. Recanalization of the treated coronary fistulae can occur, so follow-up angiography or other imaging modality should be performed in these patients.

Meeting the needs of Somali patients at the end of life.

Given the large number of Somali refugees living in Minnesota, it is likely that Minnesota physicians will encounter Somali patients, some of whom will have serious illnesses. Although our knowledge of Somali expectations about health care is growing, little has been written about the Somali people's views of treatment for life-threatening illnesses or their ideas about end-of-life care. After encountering a Somali man with advanced cancer in our practice, we attempted to learn about the Somali view of death and dying and the kind of treatment Somali patients might want during their final days. We share what we learned so that others might provide more culturally competent end-of-life care for Somali patients in the future.

Sympathetic hyperinnervation and inflammatory cell NGF synthesis following myocardial infarction in rats.

Sympathetic hyperinnervation occurs in human ventricular tissue after myocardial infarction and may contribute to arrhythmias. Aberrant sympathetic sprouting is associated with elevated nerve growth factor (NGF) in many contexts, including ventricular hyperinnervation. However, it is unclear whether cardiomyocytes or other cell types are responsible for increased NGF synthesis. In this study, left coronary arteries were ligated and ventricular tissue examined in rats 1-28 days post-infarction. Infarct and peri-infarct tissue was essentially devoid of sensory and parasympathetic nerves at all time points. However, areas of increased sympathetic nerve density were observed in the peri-infarct zone between post-ligation days 4-14. Hyperinnervation occurred in regions containing accumulations of macrophages and myofibroblasts. To assess whether these inflammatory cells synthesize NGF, sections were processed for NGF in situ hybridization and immunohistochemistry. Both macrophage1 antigen-positive macrophages and alpha-smooth muscle actin-immunoreactive myofibroblasts expressed NGF in areas where they were closely proximate to sympathetic nerves. To investigate whether NGF produced by peri-infarct cells induces sympathetic outgrowth, we co-cultured adult sympathetic ganglia with peri-infarct explants. Neurite outgrowth from sympathetic ganglia was significantly greater at post-ligation days 7-14 as compared to control tissue. Addition of an NGF function-blocking antibody prevented the increased neurite outgrowth induced by peri-infarct tissue. These findings provide evidence that inflammatory cell NGF synthesis plays a causal role in sympathetic hyperinnervation following myocardial infarction.