Cardiac post-surgery inpatients lack the amount and quality of sleep needed for optimal recovery. I aimed to investigate the non-pharmacological sleep promotion practices used by nurses and the factors that influence their use. Guided by the Theoretical Domains Framework, I developed and administered a survey to registered nurses working in the Cardiac Intensive Care Unit and the cardiac surgery ward in one cardiac centre. Findings revealed that common sleep promotion practices included orientating inpatients to the room (n=88, 96.7%), and providing additional bedding (n=86, 96.6%). The most common enablers were knowledge regarding its benefits (n=72, 100%) and an understanding of its importance (n=77, 98.7%); the most common barriers were an absence of recognition from important healthcare professionals (n=61, 85.9%) and having competing priorities (n=60, 83.3%). These findings can be used in the development of interventions to promote nurses’ use of sleep promotion practices and to improve inpatients’ sleep quality.

A 71-year-old white woman presented to her primary care physician for a routine visit and was found to have a new, previously undocumented cardiac murmur. A subsequent transthoracic echocardiogram revealed a 1 cm mobile mass arising from the lateral free wall of the left ventricle. Transesophageal echocardiography later confirmed these findings. The patient underwent a left ventriculotomy and excision of a .7 cm friable mass, which was later identified as a papillary fibroelastoma (PFE) by routine histopathologic studies. We present this unique case with a review of the literature.

The objective of this study was to determine how neurons within the right atrial ganglionated plexus (RAGP) and posterior atrial ganglionated plexus (PAGP) interact to modulate right atrial chronotropic, dromotropic, and inotropic function, particularly with respect to their extracardiac vagal and sympathetic efferent neuronal inputs. Surgical ablation of the PAGP (PAGPx) attenuated vagally mediated bradycardia by 26%; it reduced heart rate slowing evoked by vagal stimulation superimposed on sympathetically mediated tachycardia by 36%. RAGP ablation (RAGPx) eliminated vagally mediated bradycardia, while retaining the vagally induced suppression of sympathetic-mediated tachycardia (-83%). After combined RAGPx and PAGPx, vagal stimulation still reduced sympathetic-mediated tachycardia (-47%). After RAGPx alone and after PAGPx alone, stimulation of the vagi still produced negative dromotropic effects, although these changes were attenuated compared with the intact state. Negative dromotropic responses to vagal stimulation were further attenuated after combined ablation, but parasympathetic inhibition of atrioventricular nodal conduction was still demonstrable in most animals. Finally, neither RAGPx nor PAGPx altered autonomic regulation of right atrial inotropic function. These data indicate that multiple aggregates of neurons within the intrinsic cardiac nervous system are involved in sinoatrial nodal regulation. Whereas parasympathetic efferent neurons regulating the right atrium, including the sinoatrial node, are primarily located within the RAGP, prejunctional parasympathetic-sympathetic interactions regulating right atrial function also involve neurons within the PAGP.

Cardiac-specific troponins (Tns) are sensitive and specific markers of myocardial injury that have been shown to be predictive of outcomes in many cardiac and noncardiac conditions. We sought to determine whether normal cardiac Tn concentrations obtained during the first 24 hours following blunt chest trauma would predict good cardiac outcomes. A PubMed/MEDLINE search was performed to identify prospective studies in patients with blunt chest trauma in which serial cardiac TnT or TnI values were measured within 24 hours of admission and clinical outcomes assessed. Ten studies qualified for review. Studies that used the lower reference limit of Tn as the cutoff for cardiac injury showed 100% negative predictive value (NPV) for developing cardiac complications, whereas studies using higher Tn cutoffs showed wider variation in NPV (50%-98%). Cardiac Tn measured within 24 hours using the lower reference limit (LRL) as the cutoff appears to have excellent NPV for clinically significant adverse cardiac events. This could allow for early discharge after a 24-hour observation period in otherwise uncomplicated blunt chest trauma patients and avoid the need for more expensive cardiac imaging and additional resource utilization.

Aims Angiotensin II (Ang II) stimulates cardiac remodelling and fibrosis in the mechanically overloaded myocardium. Although Rho GTPases regulate several cellular processes, including myocardial remodelling, involvement in mediating mechanical stretch-induced regulation of angiotensinogen (Ao), the precursor to Ang II, remains to be determined. We, therefore, examined the role and associated signalling mechanisms of Rho GTPases (Rac1 and RhoA) in regulation of Ao gene expression in a stretch model of neonatal rat cardiac fibroblasts (CFs). Methods and resultsCFs were plated on deformable stretch membranes. Equiaxial mechanical stretch caused significant activation of both Rac1 and RhoA within 25 min. Rac1 activity returned to control levels after 4 h, whereas RhoA remained at a high level of activity until the end of the stretch period (24 h). Mechanical stretch initially caused a moderate decrease in Ao gene expression, but was significantly increased at 824 h. RhoA had a major role in mediating both the stretch-induced inhibition of Ao at 4 h and the subsequent upregulation of Ao expression at 24 h. β1 integrin receptor blockade by Tac β1 expression impaired acute (2 and 15 min) stretch-induced Rac1 activation, but increased RhoA activity. Molecular experiments revealed that Ao gene expression was inhibited by Rac1 through both JNK-dependent and independent mechanisms, and stimulated by RhoA through a p38-dependent mechanism. Conclusion These results indicate that stretch-induced activation of Rac1 and RhoA differentially regulates Ao gene expression by modulating p38 and JNK activation.

The present experiments were designed to evaluate the effects of pifithrin-α (PFT-α), which is a p53 inhibitor, on doxorubicin (DOX)-induced apoptosis and cardiac injury. Administration of DOX (22.5 mg/kg ip) in mice upregulated the mRNA levels of Bax and MDM2, whereas PFT-α attenuated those levels when administered at a total dose of 4.4 mg/kg at 30 min before and 3 h after DOX challenge. DOX treatment led to an upregulation of p53 protein levels, which was preceded by elevated levels of phosphorylated p53 at Ser15. PFT-α had no effect on the level of p53 or its phosphorylated form. The protein levels of Bax and MDM2 were elevated by DOX and attenuated by PFT-α. DOX gave rise to increased apoptosis-positive nuclei in cardiac cells, elevated serum creatine phosphokinase, ultrastructural alterations, and cardiac dysfunction. PFT-α offered protection against all of the aforementioned changes. Finally, PFT-α did not interfere with the antitumor potency of DOX. This study demonstrates that PFT-α effectively inhibits DOX-induced cardiomyocyte apoptosis, which suggests that PFT-α has the potential to protect cancer patients against DOX-induced cardiac injury.

Cardiac arrest is a common cause of coma with frequent poor outcomes. Palliative medicine teams are often called upon to discuss the scope of treatment and future care in cases of anoxic brain injury. Understanding prognostic tools in this setting would help medical teams communicate more effectively with patients’ families and caregivers and may promote improved quality of life overall. This article reviews multiple tools that are useful in determining outcomes in the setting of postarrest anoxic brain injury.

The purpose of this thesis was to better understand physical activity (PA) maintenance among patients who have completed cardiac rehabilitation (CR). Study 1: This study was a systematic review and meta-analysis of 19 randomized controlled trials (RCTs) testing PA and exercise maintenance interventions for adults who have completed CR. Descriptive synthesis of the studies combined with meta-analysis results provided evidence of increased PA among intervention groups compared with control groups at follow-up. Results of the meta-analysis found a significant difference in PA in the intervention groups compared to the control groups, via multiple exercise outcomes including exercise sessions/week (SMD = 0.20; 95% CI, 0.04 - 0.35), kcal/week (SMD = 0.59; 95% CI, 0.19 - 0.98), and daily steps (SMD = 2.14; 95% CI, 0.90 - 3.38). There is evidence to support the effectiveness of interventions aimed at maintaining PA and exercise among adults who have completed CR. Study 2: This study was a synthesis of qualitative studies examining factors affecting PA maintenance among individuals who have completed CR. Eight studies met the criteria for inclusion. Multiple factors were identified among participants, including self-efficacy and motivation, social support, support with the transition from supervised hospital or centre-based exercise to exercise in the community or home, perceived safety of the exercise program, and availability and accessibility of PA resources and opportunities. Examining qualitative literature suggests factors at the intrapersonal-, interpersonal-, organizational- and neighbourhood-level are important in supporting exercise maintenance after completion of CR. Results from this synthesis identified key areas for tailored program design, grounded in a social ecological approach. Study 3: This study was a secondary analysis of trial data examining predictors of participants’ moderate to vigorous physical activity (MVPA) 26 weeks after enrollment in a RCT of a PA maintenance intervention. Participants completed baseline questionnaires assessing social ecological, demographic, clinical, fitness, and behavioural variables. MVPA was assessed by accelerometer at baseline and 26 weeks later. Univariate analyses revealed nine significant baseline predictors of MVPA at 26 weeks including beliefs about exercise benefits, beliefs about exercise barriers, baseline MVPA, peak oxygen consumption, diabetes, age, sex, marital status, and work status. Multivariate analysis indicated that baseline MVPA was the only independent predictor of MVPA at 26 weeks. Given the pre-eminence of baseline MVPA, the regression analyses were re-run without baseline MVPA in the model. In that case, peak oxygen consumption became the only independent predictor of MVPA at 26 weeks. Results have implications for targeting intervention for PA maintenance in the unsupervised phase. Conclusion: The findings of this thesis provided insights into the influences on long-term PA among cardiac patients post-CR and the strategies which can support long-term PA. While there have been positive developments in understanding PA maintenance, there are important knowledge gaps that remain unaddressed. These knowledge gaps include the measurement, monitoring, and surveillance of PA behaviour and ways in which intervention research could be improved. Further research will be required to address these knowledge gaps and to build on the growing knowledge of effective PA interventions to support people with heart disease.

It is generally accepted that alcohol impairs haemodynamic physiology in normal subjects. Alcohol is also thought to have a detrimental effect in shock states. However, most research has concentrated on haemorrhagic shock, whereas in cardiac tamponade, the pathophysiology of shock is very different. Although some studies have mentioned alcohol as a negative factor in patients with cardiac tamponade, none have adequately assessed its effect. In a clinical study of 50 patients who presented to Groote Schuur Hospital Trauma Unit with acute cardiac tamponade due to penetrating chest injury, those who were intoxicated fared the same as their sober counterparts. Although more patients in the intoxicated group were "moribund" or "in extremis" on admission, this did not lead to a higher overall mortality. Haemodynamic parameters and results of special investigations in the two groups were also similar. These findings suggested that intoxicated patients with cardiogenic shock, specifically acute cardiac tamponade, behaved differently from intoxicated patients with haemorrhagic shock. However, the multitude of variables and the stress involved in treating patients with life-threatening acute conditions, makes studies such as this difficult. Because of these limitations, an animal model of acute cardiac tamponade was developed, so that actions of alcohol on haemodynamic physiology could be studied in a controlled environment. Fourteen young pigs were randomly assigned to receive either 30% alcohol or tap-water via a gastrostomy. The former resulted in blood alcohol levels which were compatible with moderate to severe intoxication. Cardiac tamponade was then induced by instilling warmed plasmalyte-8 into the pericardia! sac using a pressure-cycled system. Despite the fact that animals in the tamponade/alcohol group were more hypotensive, and reflex increase in heart rate was inhibited, cardiac output was similar in the two groups. The actions of alcohol in isolation were also studied in eight sham-operated pigs. The only noticeable effect in this instance were higher pulmonary artery wedge pressures in the sham/non-alcohol group. In other words, cardiac performance in both the tamponade/alcohol and sham/alcohol groups was at least equal to, or even better than that in animals that did not receive alcohol. It would seem therefore, that alcohol does not have a negative effect on haemodynamic physiology of acute cardiac tamponade. Theoretically, alcohol may "protect" patients with acute cardiac tamponade by decreasing peripheral vascular resistance and "afterload". It is also possible that inhibitory actions on the respiratory centre may prevent hyperpnoea or tachypnoea, and thereby diminish competitive filling of the right and left ventricles. However, further studies of cardiac function in intoxicated subjects with tamponade using more sophisticated techniques are necessary, before mechanisms will become apparent. In practice, an aggressive approach should be adopted towards moribund patients with penetrating chest injuries; if they have acute cardiac tamponade and are intoxicated, their prognosis is not necessarily dismal. This is of particular relevance in Cape Town, where both alcohol abuse and assault are endemic. As for a therapeutic effect of alcohol, these studies do not support its use for pharmacological manipulation of cardiac tamponade.

Indiana University-Purdue University Indianapolis (IUPUI) / Metaphors are used to conceptualize one thing in terms of another that is more familiar or concrete. The use of metaphors in patient-provider communication has helped providers generate empathy and explain concepts effectively, improving patient satisfaction and understanding of health-related concepts. With advances in technology, concepts related to health monitoring have become increasingly complex, making the potential for using metaphors in health communication at its highest relevancy. With the increase in health data there is a need to improve tools to help people understand complex information. Ethical considerations, such as possible misinterpretation of health data, as well as the potential to widen disparities because of factors such as health literacy, must be addressed. Metaphors are powerful tools that can make explanation of information accessible, accurate, and effective for people who are monitoring their data. The current research aims to contribute design recommendations for using metaphors in communication between clinicians and patients for monitoring biventricular (BiV) pacing, a complex device data element used in the monitoring of patients with heart failure (HF) who have cardiac resynchronization therapy (CRT) devices. The overarching goal is to understand this process such that it can be applied to broader communication needs in health informatics. The study addresses the following aims: Aim 1: Identify metaphors clinicians use to conceptualize BiV pacing for CRT devices using semi-structured interviews with clinician experts. Aim 2: Identify metaphors that help patients conceptualize BiV pacing for CRT devices using semi-structured interviews with patients, and exploring the metaphors identified in Aim 1. Aim 3: Develop design recommendations for health informatics interventions using an understanding of metaphors that help patients understand BiV pacing for CRT devices. Themes from analysis of Aims 1 and 2 contribute to recommendations for the use of metaphors in health informatics interventions. The purpose of this work is to contribute to an in-depth understanding of metaphors in a specific health informatics context. Importantly, this research applies methods and principles from the field of health communication to address a communication-related issue in health informatics. / 2022-12-28