Download heart and head – af and stroke.

Cardiovascular Care
Mark Curnow HASU UCH
AIMS OF SESSION
 Revision Cardiac Anatomy and physiology
 Electrical Conduction relating to ECG
 Atrial Fibrillation and stroke
 Management of Atrial Fibrillation
 Monitoring on HASU
 Blood Pressure Management
 Shock
Cardiac Anatomy and Physiology
 The heart is essentially a sophisticated muscular pump,
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propelling blood through the vascular system. It is fist
sized & lies in the mediastinum between 2nd & 6th ribs.
The heart consists of 4 chambers – right & left atria and
right & left vent. The chambers are separated by a fibro
muscular septum.
A series of 4 valves lie between the chambers;
between RA & RV - tricuspid valve
between RV & pulmonary artery - pulmonary valve
between LA & LV - mitral valve
between LV & aorta - aortic valve.
HEART ANATOMY/BLOOD FLOW
HEART ANATOMY/ BLOOD FLOW
Cardiac Cycle
BLOOD FLOW AROUND THE BODY
ELECTRICAL SYSTEM OF THE HEART
Normal Cardiac Conduction
Cardiac Conduction- Cardiac Cycle
SINUS RHYTHM
Cardiac Conduction and the ECG
DEFINITION OF AF:
Abnormal Conduction
 Most commonly sustained cardiac arrhythmia
 Atrial fibrillation is a type of arrhythmia in which the upper
chambers of the heart (the atria) beat erratically. This erratic
beating can be extremely fast (in excess of 300 beats per minute),
making it difficult for blood to circulate freely from the atria into
the lower chambers of the heart, known as the ventricles.
 AF is irregularly irregular, having no clear identifiable P waves.
Categories:
 First Episode.
 Paroxysmal: AF alternating with NSR, spontaneous reversion
 Persistent: AF alternates with NSR but requires treatment to
convert to NSR
 Permanent: Inability to convert to NSR with therapy
DEFINITION OF AF:
Abnormal Conduction
AF: CAUSES
 Most cases of AF can be attributed to diseases that
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affect the structure of the heart over many years.
Cardiomegaly: Chronic hypertension – causing
enlargement of heart muscle, in particular enlarged
atrium.
Diseases of the heart valves
Pericarditis (swelling)
Pericardial effusions (fluid around the heart )
Myocardial Infarction (damage to heart muscle)
SSS, (diseases of conduction system)
Hyperthyroidism.
Emotional stress, Nicotine, High etoh consumption
AF AND STROKE: THE PROBLEM
 AF is very common
 At least 1.3 % UK population (600,000) have known AF
 Rising to over 4% in the over 65s and 10.2% in patients
over 75 years
 AF is a major predisposing factor to stroke
 16,000 strokes annually in patients with AF in England
 Of these approx 12,500 are thought to be attributed to
AF.
AF AND STROKE: THE PROBLEM
 Incidence of people with AF developing stroke is: 4-6
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times higher than a person with no AF.
Anticoagulants: Warfarin is superior in stroke
prevention in AF.
AF strokes tend to be more severe
Warfarin reduces stroke risk by 64%
Aspirin reduces stroke risk by 22%
NICE estimate that approximately 40% of patients in
whom warfarin is indicated are not receiving it,
amounting to some 166,000 patients nationally
HOW AF CAN LEAD TO STROKE
HOW AF CAN LEAD TO STROKE
Consequence of AF- Thrombus
AF: TREATMENTS
 Dependant on type of AF and treatment aim.
 Look at history to identify any causes,
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Echocardiography to look at heart structure.
Pharmacological: Digoxin, amiodarone, Flecanide,
Beta blockers – Sotolol, Verapamil.
Non Pharmacological: Cardioversion, Ablation.
Anticoagulation if no contraindication: For prevention
of AF related complications. INR 2.o-2.5
People with Disabling ischemic stroke in AF, aspirin
300mg for 2 weeks, then consider warfarin.
ATRIAL FLUTTER
 Atrial flutter, another type of atrial arrythmia
originating from a single focus within the atrium
(usually the right) creating a rapid atrial rate from
250-400 beats per minute.
 Due to the impulse being from a single focus, the atrial
pattern on the ECG is consistent.
 As with Atrial Fibrillation, there is an increased risk of
stroke.
ATRIAL FLUTTER
MONITORING ON HASU
 HASU care provides the patient with 72 hours of acute
monitoring.
 Key element of care for people with acute stroke is
the maintenance of cerebral blood flow and
oxygenation to prevent further brain damage after
stroke (NICE)
 Cardiac Rhythm (monitor for arrhythmia)
 Blood Pressure (maintain adequate CPP, the blood
pressure gradient across the brain)
 Respiratory rate/ Oxygen Saturations (detect and
treat hypoxia) sats>95% (NICE)
Arrhythmia Detection on HASU
Bed side monitoring
 All patients on HASU monitored.
 All monitors linked to a central station with continuous
recording and recall facility.
 Bedside Monitor vs 24hr Holter Monitor
 Study (Germany) Sample of 136 patients, 29 were newly
diagnosed with PAF . 16 patients diagnosed PAF on bedside
monitor prior to commencement of 24hr tape. Of the
remaining 13 who were diagnosed PAF from bedside
monitor, 24hr tape only picked up 3.
 Therefore Continuous bedside ECG monitoring is more
sensitive than 24-hour Holter ECG for PAF detection in
acute stroke/TIA patients
 Cerebrovasc Dis. 2010;30(4):410-7.
BLOOD PRESSURE MANAGEMENT
 Blood pressure monitoring is critical.
 Anti-hypertensive treatment in people with acute
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stroke is recommended only if there is a hypertensive
emergency with one of more of the following:
hypertensive encephalopathy , hypertensive
nephropathy
hypertensive cardiac failure/myocardial infarction
aortic dissection. Pre-eclampsia/eclampsia
Intracerebral haemorrhage with systolic blood
pressure over 200 mmHg. (NICE)
ESO (2009), Deem Hypertensive emergency as BP >
systolic 220 and diastolic >120.
BLOOD PRESSURE MANAGEMENT
 Patients suitable for thrombolysis should have BP no
higher than 185/110. (NICE)
 Avoid drops in blood pressure – maintain an adequate
cerebral perfusion pressure. Usually maintained by
cerebral blood flow auto regulation.
 An intracranial event can affect auto regulation, and
an increased ICP and a decreased MAP can lower CPP
which in turn cause secondary damage to brain.
BLOOD PRESSURE TREATMENTS
 Hypertension:
 IV GTN: Mainly used in angina/ acute LVF.
Causes dilation of smooth muscle within veins and
arteries. Leading to reduced myocardial workload and
increased myocardial perfusion.
Causes hypotension. Can cause throbbing headache.
 Labetolol
Beta Blocker. Blocks beta adrenoreceptors within the
body. Reduces blood pressure by altering
baroreceptors reflex sensitivity and block peripheral
adrenoreceptors. They also cause reduction in heart
rate. CHHIPS (2009)
SHOCK
 Types:
Cardiogenic: Pump Failure. Diminished cardiac
output which severely impairs tissue perfusion.
Causes: Myocardial Infarction / Ischemia
End stage Cardiomyopathy
Signs :
Cold, pale clammy skin
Hypotension. Tachycardia.
Reduced urine output. Confusion.
Treatment: Fluid challenge. Inotropes. IABP.
Septic Shock
Hypovoleamic.
CONCLUSION
Remember:
 Close monitoring is essential on HASU
 Familiarise yourself with the monitor (don't be scared
of it)
 Observe cardiac rhythm for changes, especially
irregularities.
 Monitor Hemodynamics, agree parameters with team
and manage changes early.
 Knowledge leads to empowerment. Always aim to
learn from your experiences by questioning, then tell
someone else!!
THANK YOU