Assessment of Myocardial Injury Size Metrics Using Carotid Pressure Waveform: Proof-of-Concept in Coronary Occlusion/Reperfusion Rat Model.

Myocardial infarction (MI) is a leading cause of death worldwide and the most common precursor to heart failure, even after initial treatment. Precise evaluation of myocardial injury is crucial for assessing interventions and improving outcomes. Extensive evidence from both preclinical models and clinical studies demonstrates that the extent and severity of myocardial injury (i.

Assessment of left ventricular relaxation time constant using arterial pressure waveform.

Instantaneous determination of left ventricular (LV) diastolic function would be a useful aid in diagnosis and treatment of heart failure. The time constant of LV pressure decay (also known as Tau) is an established metric for evaluating LV stiffness and assessing LV diastolic function. Approach: In this study, we present a novel approach that uses a single arterial (aortic) pressure waveform to classify abnormal Tau through a physics-based machine learning (ML) methodology.

Time-frequency machine learning transfer function for central pressure waveforms.

Aims: Clinical studies show that pulsatile haemodynamics and pressure waveform analysis are valuable for the diagnosis and prognosis of hypertension and heart failure (HF). While generalized transfer functions (GTFs) have shown clinical significance, some studies report limitations with GTF in capturing central pulsatile haemodynamics. This study introduces a hybrid time-frequency, machine learning-based transfer function that reconstructs central pressure waveforms from peripheral measurements, accurately capturing central pulsatile haemodynamics and arterial wave-based information.

Empagliflozin demonstrates neuroprotective and cardioprotective effects by reducing ischemia/reperfusion damage in rat models of ischemic stroke and myocardial infarction.

Sodium-glucose co-transporter 2 (SGLT2) inhibitors have demonstrated potential neuroprotective and cardioprotective effects in preliminary studies. This study evaluates the efficacy of empagliflozin (EMPA) in reducing ischemia/reperfusion damage in both the brain and heart using rat models. Ischemic stroke and myocardial infarction (MI) were induced in male Sprague-Dawley rats, which were randomized into three groups: (1) Control (no EMPA), (2) Acute treatment (EMPA, 10 mg/kg IV, administered 10 min before ischemia and 1 min before reperfusion), and (3) Chronic treatment (EMPA, 20 mg/kg in food for 7 days before ischemia).

Indirect Ballistic Injury Resulting in Non-ST-Segment Elevation Myocardial Infarction.

Gunshot-related myocardial injuries typically result from direct penetrating injury by the traversing bullet. We present a case of gunshot-related myocardial injury in the absence of direct penetrating injury to the cardiac structures and describe alternative mechanisms for ballistic-induced injury.

Adverse Cardiovascular Effects of Nicotine Delivered by Chronic Electronic Cigarettes or Standard Cigarettes Captured by Cardiovascular Intrinsic Frequencies.

Background: Electronic cigarettes have gained popularity as a nicotine delivery system, which has been recommended by some as an aid to help people quit traditional smoking. The potential long-term effects of vaping on the cardiovascular system, as well as how their effects compare with those from standard cigarettes, are not well understood. The intrinsic frequency (IF) method is a systems approach for analysis of left ventricle and arterial function.

Detecting elevated left ventricular end diastolic pressure from simultaneously measured femoral pressure waveform and electrocardiogram.

Instantaneous, non-invasive evaluation of left ventricular end-diastolic pressure (LVEDP) would have significant value in the diagnosis and treatment of heart failure. A new approach called cardiac triangle mapping (CTM) has been recently proposed, which can provide a non-invasive estimate of LVEDP. We hypothesized that a hybrid machine-learning (ML) method based on CTM can instantaneously identify an elevated LVEDP using simultaneously measured femoral pressure waveform and electrocardiogram (ECG).

A machine learning approach for computation of cardiovascular intrinsic frequencies.

Analysis of cardiovascular waveforms provides valuable clinical information about the state of health and disease. The intrinsic frequency (IF) method is a recently introduced framework that uses a single arterial pressure waveform to extract physiologically relevant information about the cardiovascular system. The clinical usefulness and physiological accuracy of the IF method have been well-established via several preclinical and clinical studies.

Instantaneous detection of acute myocardial infarction and ischaemia from a single carotid pressure waveform in rats.

Aims: Myocardial infarction (MI) is one of the leading causes of death worldwide. It is well accepted that early diagnosis followed by early reperfusion therapy significantly increases the MI survival. Diagnosis of acute MI is traditionally based on the presence of chest pain and electrocardiogram (ECG) criteria.

Assessment of Aortic Characteristic Impedance and Arterial Compliance from Non-invasive Carotid Pressure Waveform in The Framingham Heart Study.

The primary goal of this study was to test the hypothesis that a hybrid intrinsic frequency-machine learning (IF-ML) approach can accurately evaluate total arterial compliance (TAC) and aortic characteristic impedance (Zao) from a single noninvasive carotid pressure waveform in both women and men with heart failure (HF). TAC and Zao are cardiovascular biomarkers with established clinical significance. TAC is lower and Zao is higher in women than in men, so women are more susceptible to the consequent deleterious effects of them.

A coupled atrioventricular-aortic setup for in-vitro hemodynamic study of the systemic circulation: Design, fabrication, and physiological relevancy.

In-vitro models of the systemic circulation have gained a lot of interest for fundamental understanding of cardiovascular dynamics and for applied hemodynamic research. In this study, we introduce a physiologically accurate in-vitro hydraulic setup that models the hemodynamics of the coupled atrioventricular-aortic system. This unique experimental simulator has three major components: 1) an arterial system consisting of a human-scale artificial aorta along with the main branches, 2) an artificial left ventricle (LV) sac connected to a programmable piston-in-cylinder pump for simulating cardiac contraction and relaxation, and 3) an artificial left atrium (LA).

Effects of vessel wall mechanics on non-invasive evaluation of cardiovascular intrinsic frequencies.

Intrinsic Frequency (IF) is a systems-based approach that provides valuable information for hemodynamic monitoring of the left ventricle (LV), the arterial system, and their coupling. Recent clinical studies have demonstrated the clinical significance of this method for prognosis and diagnosis of cardiovascular diseases. In IF analysis, two dominant instantaneous frequencies (ω and ω) are extracted from arterial pressure waveforms.

Scalability of cardiovascular intrinsic frequencies: Validations in preclinical models and non-invasive clinical studies.

Aims: Cardiovascular intrinsic frequencies (IFs) are associated with cardiovascular health and disease, separately capturing the systolic and diastolic information contained in a single (uncalibrated) arterial waveform. Previous clinical investigations related to IF have been restricted to studying chronic conditions, and hence its applicability for acute cardiovascular diseases has not been explored. Studies of cardiovascular complications such as acute myocardial infarction are difficult to perform in humans due to the high-risk and invasive nature of such procedures.