Ischaemic Heart Disease

Exertional chest pain that is completely predictable and relieved within minutes by rest or sublingual nitroglycerine defines [...], whereas pain appearing abruptly at rest lasting more than 20 minutes indicates [...].

stable angina, acute coronary syndrome

List the 4 clinical features of chest pain that strongly suggest a non-ischemic etiology rather than myocardial ischemia.

sharp or stabbing, pleuritic, localized with a single fingertip, reproducible with movement or chest wall palpation

During coronary atherogenesis, monocytes migrate into the intimal layer and differentiate into macrophages which ingest oxidized low-density lipoproteins to become [...], aggregating into early structural [...].

foam cells, fatty streaks

List the 5 specific architectural characteristics that define a high-risk or vulnerable atherosclerotic plaque prone to acute rupture.

large lipid core, thin fibrous cap, high density of macrophages and lymphocytes, paucity of smooth muscle cells, increased neovascularity

Which specific family of enzymes is secreted by activated macrophages to digest structural collagen within the protective fibrous cap, triggering plaque disruption?

matrix metalloproteinases

A partial or transiently occlusive coronary thrombus results in myocardial ischemia localized to the [...] layer, whereas complete persistent occlusion causes full-thickness [...] necrosis.

subendocardial, transmural

What is the mechanical explanation for a classic S4 heart sound auscultated during an acute myocardial infarction?

atrial contraction into a stiff non-compliant left ventricle

What clinical finding does an S3 heart sound indicate during an acute myocardial infarction presentation?

elevated left ventricular filling pressures or acute heart failure

Serum cardiac troponin I or T does not increase significantly until at least [...] hours after symptom onset, and its persistent elevation for [...] days limits its utility for diagnosing acute re-infarction.

6, 5 to 14

Which cardiac biomarker is the investigation of choice to diagnose early recurrent myocardial re-infarction, and why?

CK-MB, because of its short half-life and rapid clearance profile

Acute ST-segment elevation or a new Left Bundle Branch Block localized strictly to leads II, III, and aVF confirms an acute [...] wall myocardial infarction, typically caused by occlusion of the [...].

inferior, right coronary artery

List the 7 discrete clinical parameters evaluated in the TIMI scoring system for unstable angina and NSTEMI risk stratification.

age 65 years or older, three or more cardiovascular risk factors, known coronary artery disease with stenosis 50 percent or greater, aspirin use within the last 7 days, two or more anginal episodes within 24 hours, ST deviation 1 mm or greater, elevated serum cardiac biomarkers

The GRACE score evaluates 6-month mortality in NSTEMI using 8 parameters, including heart failure severity via the [...] classification, where class IV represents [...].

Killip, cardiogenic shock

List the 6 high-risk clinical features that warrant the administration of supplemental oxygen in an acute coronary syndrome presentation.

ongoing rest pain lasting more than 20 minutes, clinical features of heart failure, systemic hypotension, bradycardia, severe tachycardia, bundle branch block

Intravenous Morphine relieves acute ischemic pain and unloads the heart by inducing [...], which directly reduces both [...] and afterload.

venodilation, preload

What is the exact oral loading dose of chewed non-enteric coated Aspirin required immediately in acute coronary syndrome, and what is its molecular target?

150 mg to 325 mg, irreversible inhibition of the COX-1 enzyme to shut down thromboxane A2 production

When using parenteral enoxaparin for acute coronary syndrome, what is the weight-based maintenance infusion threshold for a patient weighing over 80 kg versus under 80 kg?

1000 IU per hour for over 80 kg, 800 IU per hour for under 80 kg

Why is the concurrent administration of oral beta-blockers and non-dihydropyridine calcium channel blockers like verapamil strictly contraindicated?

high risk of precipitating fatal bradycardia, severe hypotension, or complete AV heart block

What catastrophic clinical interaction occurs if a patient taking organic nitrates for angina co-administers a phosphodiesterase-5 inhibitor like Viagra or Cialis?

severe life-threatening synergistic hypotension

List the 4 clinical indicators that mandate the initiation of an ACE inhibitor within the first 24 hours of an acute myocardial infarction.

reduced systolic ejection fraction, active congestive heart failure, documented anterior wall infarction, active bundle branch block

All patients presenting with a documented STEMI within [...] hours of symptom onset must undergo immediate hyperacute reperfusion, preferably via [...].

12, primary percutaneous coronary intervention

Fibrinolytic agents like Streptokinase yield dramatic survival benefits if given within the first [...] hour, but are absolutely contraindicated in patients with a history of recent [...].

1, stroke or active internal bleeding

Why is systemic thrombolytic therapy strictly contraindicated in Unstable Angina and NSTEMI presentations?

it increases bleeding from the ruptured plaque matrix, paradoxically accelerating plaque destabilization and triggering complete STEMI occlusion

What is the primary cause of sudden cardiac death during the hyperacute phase of a myocardial infarction, and what structural system is injured?

ventricular tachyarrhythmias, ischemic injury to the specialized conduction system

Pathologic post-myocardial infarction ventricular remodeling involves myocyte loss and interstitial [...] that stiffens the ventricle, clinically presenting as left-sided heart failure with [...].

fibrosis, orthopnoea and paroxysmal nocturnal dyspnoea