EPDM 566 Epid of CVD Definitions of IHD

  • Slides: 22
Download presentation
EPDM 566 – Epid of CVD Definitions of IHD R. Knutsen

EPDM 566 – Epid of CVD Definitions of IHD R. Knutsen

Background • Leading cause of death in developed countries. • Remains responsible for about

Background • Leading cause of death in developed countries. • Remains responsible for about one-third of all deaths over age 35. • Nearly one-half of all middle-aged men and one-third of middle-aged women in the United States will develop some manifestation of CHD

Definitions • Accuracy in assessment of both exposure and outcome is crucial for good

Definitions • Accuracy in assessment of both exposure and outcome is crucial for good epidemiologic studies. • Without careful, detailed and standardized criteria for exposure and outcomes, a study will have major flaws and can jeopardize the whole study.

Definition • Coronary heart disease (CHD) = coronary artery disease (CAD) = atherosclerotic heart

Definition • Coronary heart disease (CHD) = coronary artery disease (CAD) = atherosclerotic heart disease • End result of the accumulation of atheromatous plaques within the walls of the arteries that supply the myocardium (the muscle of the heart). • Symptoms and signs are noted in the advanced state of disease • ICD-9 -CM codes: – 410 (acute MI) – 411 (other acute and subacute forms of IHD); 412 (history of MI) – 413 (angina pectoris) – 414 (all other forms of chronic IHD) • ICD-10 -CA codes: I 20 - I 25 (ischemic heart diseases)

Coronary Heart Disease Ischemia: Oxygenized blood does not reach the cells Caused by: •

Coronary Heart Disease Ischemia: Oxygenized blood does not reach the cells Caused by: • Coronary muscle cells become ischemic (do not receive sufficient blood supply) • A combination of two processes: – atherosclerosis – platelet-vessel wall interactions

Coronary Heart Disease

Coronary Heart Disease

Clinical symptoms • Heart – Angina Pectoris ( greek: angere = to choke) –

Clinical symptoms • Heart – Angina Pectoris ( greek: angere = to choke) – Myocardial infarction (heart attack) – Sudden cardiac death • Brain – TIA – transitory ischemic attack – Stroke – hemorrhagic or thromboembolic • Other organs: Kidney, GI tract, Lower extremities – Claudication, Gangrene

Angina Pectoris • Simply chest pain, discomfort, heaviness, pressure, aching, burning, fullness, squeezing, or

Angina Pectoris • Simply chest pain, discomfort, heaviness, pressure, aching, burning, fullness, squeezing, or painful feeling. • Angina is usually felt in the chest, but may also be felt in the shoulders, arms, neck, throat, jaw, or back. • Pain caused by Lactic acid • Can occur in the absence of CAD

Types of Angina • Stable angina - The pain is predictable and present only

Types of Angina • Stable angina - The pain is predictable and present only during exertion or extreme emotional distress, and it disappears with rest • Unstable angina - May signal an impending heart attack. May occur more frequently, more easily at rest, feel more severe, last longer, or come on with minimal activity • Prinzmetal's angina - Occurs at rest, when sleeping, or when exposed to cold temperatures. Symptoms caused by decreased blood flow to the heart muscle from a spasm of the coronary artery

International criteria for other CHD • Angina Pectoris - More unspecific diagnosis - Debate

International criteria for other CHD • Angina Pectoris - More unspecific diagnosis - Debate about the criteria to be used - In epidemiologic research, one of the best tools has been the Rose Questionnaire u u Asks about chest pain in different situations Has been the standard for this diagnosis in epidemiologic studies for decades Clinicians will often insist that ischemic changes must be present on the ECG during stress testing in order to make this diagnosis However, in epidemiologic studies where one cannot do ECG on all subjects and also because ECG is not a highly specific test for diagnosing AP, a positive response on the Rose questionnaire has been found to be a good predictor of later development of MI

The Rose Questionnaire

The Rose Questionnaire

Myocardial Infarction Important to use standard criteria for diagnosis Ex: Criteria have changed over

Myocardial Infarction Important to use standard criteria for diagnosis Ex: Criteria have changed over time 1. Acute retrosternal pain and elevated sedimentation rate 2. Acute retrosternal pain, elevated enzyme levels specific for MI, typical ECG findings 3. Acute retrosternal pain, typical findings on imaging or angiography, enzyme elevation and ECG findings.

Myocardial Infarction When comparing incidence rates of MI in different studies, it is important

Myocardial Infarction When comparing incidence rates of MI in different studies, it is important to confirm that the same diagnostic criteria were used to make the diagnosis If not, we will be “comparing apples and oranges”

The International criteria for diagnosing acute, non-fatal MI (Am Heart J 1984; 108: 150

The International criteria for diagnosing acute, non-fatal MI (Am Heart J 1984; 108: 150 -58) • • Typical ECG findings – elevated ST segments or Elevated enzyme levels (Creatine Kinase, troponin) within the first few days – as myocardial muscle cells die, intracellular enzymes specific for the myodcardium leak into the blood and can be measured in the serum. and Acute, typical and prolonged cardiac pain or Static ECG abnormalities With new types of treatment, these criteria need revision

The International criteria for other CHD (Am Heart J 1984; 108: 150 -58) •

The International criteria for other CHD (Am Heart J 1984; 108: 150 -58) • Fatal CHD – – • Definite fatal myocardial infarction (death within 30 days following MI as defined by international criteria or Other definite fatal CHD Sudden death – – Witnessed, unexpected , non-traumatic, non self-inflicted death in a subject with or without pre-existing cardiac disease within 1 hour from onset of symptoms or When death is unwitnessed – unexpected, non-traumatic, non self-inflicted death in a subject with or without pre-existing cardiac disease who has been seen to be well within the preceding 24 hours

Stroke Anatomy of the inside of the skull Skull Cerebrospinal fluid Dura mater Arachnoid

Stroke Anatomy of the inside of the skull Skull Cerebrospinal fluid Dura mater Arachnoid Pia mater Brain

Non-stroke hemorrhage Epidural hemorrhage Skull Cerebrospinal fluid Dura mater Arachnoid Pia mater Brain

Non-stroke hemorrhage Epidural hemorrhage Skull Cerebrospinal fluid Dura mater Arachnoid Pia mater Brain

Non-stroke hemorrhage Subdural hemorrhage Cerebrospinal fluid Skull Dura mater Arachnoid Pia mater Brain

Non-stroke hemorrhage Subdural hemorrhage Cerebrospinal fluid Skull Dura mater Arachnoid Pia mater Brain

Stroke Ischemic stroke Subarachnoid hemorrhage Cerebrospinal fluid Skull Dura mater Arachnoid Pia mater Brain

Stroke Ischemic stroke Subarachnoid hemorrhage Cerebrospinal fluid Skull Dura mater Arachnoid Pia mater Brain Cerebral hemorrhage

Different strokes • Transitory Ischemic Attack (TIA) – Temporary lack of blood supply to

Different strokes • Transitory Ischemic Attack (TIA) – Temporary lack of blood supply to a apart of the brain because of spasms in an atherosclerotic vessel • Cerebral hemorrhage – Rupture of an atherosclerotic artery causing hemorrhage within the brain or on the outside of the brain. – Causes compression and destruction of the brain and pressure symptoms

Different strokes • Ischemic (or thromboembolic) stroke – An atherosclerotic artery is occluded by

Different strokes • Ischemic (or thromboembolic) stroke – An atherosclerotic artery is occluded by either thrombus or by a clot (emboli) from somewhere else in the body. The result is lack of blood supply and necrosis of the part of the brain supplied by this artery. • Subarachnoid hemorrhage – acute hemorrhage in one of the vessels in the arachnoid membrane resulting in massive bleeding into the subarachnoid space.

Different strokes • In the past, it was virtually impossible to distinguish between hemorrhagic

Different strokes • In the past, it was virtually impossible to distinguish between hemorrhagic and thromboembolic stroke. Only autopsy would reveal whether it was one or the other. • New diagnostic tools such as CAT-scan and MRI, make it possible to differentiate between the two and also be able to diagnose much smaller strokes which in the past often were thought to be signs of dementia.