Carotid Reservoir Pressure Decrease After Prolonged Head Down Tilt Bed Rest in Young Healthy Subjects Is Associated With Reduction in Left Ventricular Ejection Time and Diastolic Length

BACKGROUND: The arterial pressure waveform reflects the interaction between the heart and the arterial system and carries potentially relevant information about circulatory status. According to the commonly accepted ‘wave transmission model’, the net BP waveform results from the super-position of discrete forward and backward pressure waves, with the forward wave in systole determined mainly by the left ventricular (LV) ejection function and the backward by the wave reflection from the periphery, the timing and amplitude of which depend on arterial stiffness, the wave propagation speed and the extent of downstream admittance mismatching. However, this approach obscures the ‘Windkessel function’ of the elastic arteries. Recently, a ‘reservoir-excess pressure’ model has been proposed, which interprets the arterial BP waveform as a composite of a volume-related ‘reservoir’ pressure and a wave-related ‘excess’ pressure. METHODS: In this study we applied the reservoir-excess pressure approach to the analysis of carotid arterial pressure waveforms (applanation tonometry) in 10 young healthy volunteers before and after a 5-week head down tilt bed rest which induced a significant reduction in stroke volume (SV), end-diastolic LV volume and LV longitudinal function without significant changes in central blood pressure, cardiac output, total peripheral resistance and aortic stiffness. Forward and backward pressure components were also determined by wave separation analysis. RESULTS: Compared to the baseline state, bed rest induced a significant reduction in LV ejection time (LVET), diastolic time (DT), backward pressure amplitude (bP) and pressure reservoir integral (INTPR). INTPR correlated directly with LVET, DT, time to the peak of backward wave (bT) and stroke volume, while excess pressure integral (INTXSP) correlated directly with central pressure. Furthermore, Δ.INTPR correlated directly with Δ.LVET, and Δ.DT, and in multivariate analysis INTPR was independently related to LVET and DT and INTXSP to central systolic BP. CONCLUSION: This is an hypothesis generating paper which adds support to the idea that the reservoir-wave hypothesis applied to non-invasively obtained carotid pressure waveforms is of potential clinical usefulness

Not only Van Gogh: a case of BRASH syndrome with concomitant digoxin toxicity

Background Bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia syndrome is a potentially life-threatening clinical condition characterized by bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia. It constitutes a vicious circle in which the accumulation of pharmacologically active compounds and hyperkalemia lead to hemodynamic instability and heart failure.Case presentation A 66-year-old Caucasian female patient was admitted to the emergency department presenting with fatigue and bradycardia. Upon examination, the patient was found to be anuric and hypotensive. Laboratory investigations revealed metabolic acidosis and hyperkalemia. Clinical evaluation suggested signs of digoxin toxicity, with serum digoxin concentrations persistently elevated over several days. Despite the implementation of antikalemic measures, the patient's condition remained refractory, necessitating renal dialysis and administration of digoxin immune fab.Conclusion Bradycardia, renal failure, atrioventricular (AV) node blocking, shock, and hyperkalemia syndrome is a life-threatening condition that requires prompt management. It is important to also consider potential coexisting clinical manifestations indicative of intoxication from other pharmacological agents. Specifically, symptoms associated with the accumulation of drugs eliminated via the kidneys, such as digoxin. These manifestations may warrant targeted therapeutic measures

Grandi arterie e accoppiamento ventricolo-arterioso nell'obesità patologica prima e dopo decremento ponderale

L'elaborato si propone, fornita una preliminare analisi dei principi basilari della fisiologia cardiaca, di valutare quelli che sono i modelli teorici più diffusi, e storicamente più importanti, rappresentanti il sistema cardiovascolare, al fine di esaltarne i punti di forza e, nel contempo, evidenziarne i limiti. Quindi, si introdurranno i concetti, relativamente nuovi, di wave intensity analysis e reservoir wave model, al fine di superare le problematiche mostrate dai modelli classici. Infine, ci si focalizzerà sull'applicazione pratica di questi modelli in un protocollo sperimentale concernente l'analisi di soggetti obesi, prima e dopo decremento ponderale, al fine di individuare, i meccanismi fisiopatologici che si celano dietro l'aumento del rischio cardiovascolare in questa popolazione. Aumento del rischio che si rifletterà nell’alterazione di quei parametri che, in accordo con i succitati modelli, predicono il comportamento del sistema cardiovascolare; parametri che poi, si normalizzeranno in ragione della perdita di massa corporea e di tessuto adiposo, come confermato dai test statici condotti, confermandone sensibilità e accuratezza

Gap junction modulators: Prospects in bupropion cardiotoxicity

Bupropion, a multifaceted antidepressant, is associated with serious cardiotoxicity when misused. Recently, there has been a noticeable increase in cases of intentional poisoning and current therapeutic interventions for bupropion overdose remain insufficient. The cardiotoxic effects of the drug are primarily linked to its influence on cardiac gap junctions. Small-molecule drugs enhancing gap junction conductance, such as rotigaptide and danegaptide, present potential as antidotal agents. Testing these molecules under conditions of bupropion overdose could address the urgent need for innovative approaches to mitigate bupropion-induced cardiotoxicity

LOW CAROTID ARTERIAL STIFFNESS IN YOUNG TYPE1 DIABETIC PATIENTS COMPARED WITH AGE-MATCHED CONTROLS

Background: Local pulse wave velocity (c) is widely used as an index of local carotid arterial stiffness. In middle-aged type1 and type2 diabetic patients, arterial stiffness is higher than in healthy people, but much less data are available for young subjects. Our aim was to quantify the changes in c asso- ciated with ageing and type1 diabetes in young patients. Methods: Pressure and diameter waveforms of healthy control (n Z 53, 29 male, mean age 39 ` 17) and type1 diabetic (n Z 20, 15 male, mean age 19 ` 2.5) subjects have been acquired simultaneously using tonometry (500 or 1000Hz) and an ultrasound probe (1kHz) at the level of the left and right common carotid artery, respectively. The geometrical similarity between the right and left common carotid artery was verified, and the two signals were assumed as recorded at the same site. The PD2-loop method [1] was used to calculate c in late diastole as follow: c Z D0dPr d(D2). Results: In controls, c remained approximately constant up to ages 35e44y, at `4 m/s. From 45e54 years old, c increased up to 7m/s in elderly subjects (figure1-left). In young diabetic subjects (15e24), c was lower than in aged- matched control subjects (mean `95% C.I., diabetic 3.51 ` 0.007 and con- trol 3.78 ` 0.005, p < 0.05) (figure1-right). Conclusions: Local stiffness increases with age in the human carotid artery. As found for the descending thoracic aorta previously[2], younger T1 diabetic patients may have more compliant vessels initially, aggravating their ten- dency to stiffen later

Laurel but Hardy: unintended poisoning, a case report of oleander misidentification as bay laurel

Introduction: Nerium oleander is a toxic plant containing cardiac glycosides throughout all its parts, thereby posing severe health risks upon ingestion. The clinical manifestations of oleander poisoning closely resemble those of digoxin toxicity, encompassing a spectrum of gastrointestinal symptoms, neuropsychiatric disorders, and cardiac disturbances. This scientific case report describes a case of accidental intoxication resulting from the consumption of an oleander leaves infusion misidentified as bay laurel leaves. Case report: An 84-year-old patient consumed an oleander leaves infusion, and after four hours experienced gastrointestinal symptoms. He contacted the poison control center (PCC) and was advised to go to the emergency department (ED). Upon arrival, the patient presented stable vital signs without cardiac irregularities. The PCC recommended the administration of activated charcoal, vigilant monitoring, including electrocardiography (ECG). Subsequent ECGs assessments revealed the presence of third-degree atrioventricular block; in consultation with the PCC, digoxin-specific antibodies and external pacing were necessary. The patient was discharged on the eighth day in good hemodynamic condition, and outpatient follow-up visits showed clinical stability. Discussion: This study offers insights for the management of similar cases. The limitations of conventional assays in measuring oleander cardiac glycosides were observed, emphasizing reliance on clinical evaluation. The patient's trajectory, remaining asymptomatic despite severe ECG changes post-ingestion, underscores the importance of prolonged clinical monitoring

“Heavy Metal”: Management of lead toxicity following a gunshot injury with retained lead fragments, a case report

: There is limited literature on managing chronic lead exposure from non-removable sources such as lead fragments. In this case report, we present the complexities and clinical considerations involved in treating an elderly patient who sustained a comminuted knee fracture due to a gunshot wound, complicated by retained lead fragments. This case highlights the absence of comprehensive guidelines for managing chronic lead exposure when complete fragment removal is impractical. It also emphasizes the importance of a multidisciplinary approach to decision-making, while considering patient autonomy in such unique clinical scenarios