Cardiovascular CareMark Curnow HASU UCH

AIMS OF SESSIONRevision Cardiac Anatomy and

physiologyElectrical Conduction relating to ECGAtrial Fibrillation and strokeManagement of Atrial FibrillationMonitoring on HASUBlood Pressure ManagementShock

Cardiac Anatomy and PhysiologyThe heart is essentially a sophisticated muscular

pump, 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 valvebetween RV & pulmonary artery - pulmonary valvebetween LA & LV - mitral valvebetween 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 arrhythmiaAtrial 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 reversionPersistent: AF alternates with NSR but requires treatment to

convert to NSRPermanent: Inability to convert to NSR with therapy

DEFINITION OF AF: Abnormal Conduction

AF: CAUSES Most cases of AF can be attributed to diseases

that 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 valvesPericarditis (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 PROBLEMAF is very commonAt least 1.3 % UK population (600,000) have

known AFRising to over 4% in the over 65s and 10.2%

in patients over 75 yearsAF is a major predisposing factor to stroke16,000 strokes annually in patients with AF

in EnglandOf these approx 12,500 are thought to be

attributed to AF.

AF AND STROKE: THE PROBLEMIncidence of people with AF developing

stroke is: 4-6 times higher than a person with no AF.

Anticoagulants: Warfarin is superior in stroke prevention in AF.

AF strokes tend to be more severeWarfarin 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 STROKEConsequence of AF- Thrombus

AF: TREATMENTSDependant on type of AF and treatment aim. Look at history to identify any causes,

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 HASUHASU 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 HASUBed 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 MonitorStudy (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 MANAGEMENTBlood pressure monitoring is critical. Anti-hypertensive treatment in people with acute

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 MANAGEMENTPatients 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 TREATMENTSHypertension: 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)

SHOCKTypes: 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 HASUFamiliarise 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