By: Prof. Dr. Seyed Saeid Zamanieh Shahri, MD and Prof. Dr. Sonia Sayyedalhosseini, MD
7. Diagnostic Methods:
Diagnosis of myocardial infarction in modern literature relies on integrating clinical data, ECG findings, and high-sensitivity biomarkers within algorithmic pathways:
• a) Electrocardiogram (ECG):
The 12-lead ECG remains the primary tool for the initial classification of myocardial infarction. Recognition of characteristic or equivalent patterns, alongside the clinical picture, plays a central diagnostic role.
• b) High-sensitivity cardiac troponin:
A rise and/or fall in troponin is essential to define myocardial injury, and when accompanied by evidence of ischemia, confirms infarction.
• c) Non-invasive imaging:
Coronary CT angiography is a key modality for assessing coronary anatomy and plaque burden.
• d) Diagnostic classifications:
Modern criteria delineate “injury” versus “infarction” and specify type categories based on combined clinical, laboratory, and imaging evidence. Thus, an updated diagnostic report typically integrates: symptoms, dynamic biomarker changes, imaging evidence of ischemia/perfusion deficit, and documentation of procedural events.
8. Advances in Technology:
Recent years have seen major technological trends in the diagnosis and monitoring of myocardial infarction:
• High-sensitivity troponin algorithms and accelerated evaluation pathways.
• Computational coronary imaging and non-invasive physiological assessment.
• Artificial intelligence applied to standard ECG interpretation.
• Integrated data systems unifying multi-source clinical information for decision support.
Summary: Conceptually, myocardial infarction is an ischemic-necrotic event within the heart muscle, defined by biomarker patterns, imaging findings, and clinical context. The Fourth Universal Definition provides a shared terminology and framework, outlining types 1 to 5 with distinct mechanisms. At the population level, its risk profile parallels that of classical atherosclerosis, while clinical presentations range from typical pressure-like chest pain to atypical forms. Complications include electrical, hemodynamic, structural, and thromboembolic disorders. Diagnostic strategies center on ECG and high-sensitivity troponin measurements using short-interval (0/1-hour and 0/2-hour) algorithms, complemented by advanced imaging such as CT angiography. On the technological front, artificial intelligence–enhanced ECG analysis and computational physiology modeling represent key emerging trends.
Definition of Hypertension: Hypertension is a persistent condition in which the pressure exerted on arterial walls remains chronically above the accepted range observed in a healthy population. This definition relies on repeated measurements of systolic and diastolic blood pressure under standardized conditions and emphasizes the sustained elevation of values.
Although numerical thresholds vary slightly across professional guidelines, the core shared element is the presence of a “persistent increase in arterial pressure” capable of producing structural and functional consequences in target organs.
Blood pressure represents the product of cardiac output and peripheral vascular resistance; any chronic increase in either component can generate hypertension. The condition may be primary/essential (without a single identifiable cause) or secondary (arising from a specific underlying disorder).
Pathophysiology: The pathophysiology of hypertension consists of an interconnected network of overlapping mechanisms:
1. Cardiac output and peripheral vascular resistance:
Cardiac output (heart rate × stroke volume) and systemic vascular resistance are the direct determinants of arterial pressure. In many individuals, cardiac output remains within normal limits, and sustained elevation of vascular resistance, due to vasoconstriction and structural remodeling of arteriolar walls, becomes the dominant factor.
2. Renin–angiotensin–aldosterone system (RAAS):
Production of angiotensin II (a potent vasoconstrictor) and aldosterone secretion (promoting sodium and water retention) drive increases in both vascular resistance and intravascular volume. To Be Countinued
