TELL ME AND I FORGET. TEACH ME AND I

REMEMBER. INVOLVE ME AND I

LEARNED.

•BENJAMIN FRANKLIN

CIRCULATION

CARDIAC PHYSIOLOGY& PARAMETER

VOLUME

SV=ENDDIASTOLIC VOLUME-ENDSYSTOLIC VOLUME

CARDIAC OUTPUT=HRXSV

AFTERLOAD AND PRELOAD

EF=STROKE VOLUME/END DIASRTOLIC VOLUME

TROPISM

INOTROPIC (CONCRACTILITY)

CHRONOTROPIC (CHANGE HEART RATE)

DROMOTROPIC (CONDUCTION VELOCITY)

BATHMOTROPIC (EXCITABULITY)

LUSITROPIC ( RELAXATION)

CONDUCTION SYSTEM

Cardiac action potential

Atrial action potential

Ventricular action potential

Effective refractory period

Pacemaker potential

CHAMBER

PRESSURECVP, RVP,PULMONARY ARTERY PRESSURE,

LEFT ATRIAL PRESSURE, LT. VENTRICULAR PRESSURE, AORTIC PRESSURE

BLOOD PRESSURE

PULSE PRESSURE=SBP-DBP

ATREIAL BP=SYSTOLIC (90-140),DIASTOLIC (60-90)

MEAN ARTERIAL PRESSURE=SBP+(2XDBP)/3 (70-105mmHg)

Right atrial pressure (2-6mmHG)

RIGHT VENTRICULAR PRSEEURE (RVP)

SYSTOLIC (SRVP):15-25mmHG

DIASTOLIC (DRVP);0-8mmHg

PULMONARY ARTERY PRESSURESYSTOLIC (PASP):15-25mmHg

DIASTOLIC (PADP):8-15mmHg

ROLES OF AUTONOMIC NURVOUS SYSTEMS

SYMPATHETICPARASYMPATHETIC

ADRENERGIC

RECEPTOR

CATECHOLAMINES

EPINEPHRINE/

NOREPINEPHRINE

ACETYLCHOLINE

INCREASED HEART

RATE, BP,CO,

VASOCONSTRICTION,

DECREASED

HR,CO,BP,VASODILATION

REST AND DIGESTFLIGHT OR FIGHT

PHYSIOLOGICAL TACHYCARDIA AND BRADYCARDIA..WHY??

human heart electrical system

INTRODUCTION

Heart rate, or heart pulse, is the speed of

the heartbeat measured by the number of

heartbeats per unit of time (bpm).

The heart rate can vary according to the

body's physical needs, including the need

to absorb oxygen and excrete carbon

dioxide.

Activities that can provoke change

include physical exercises, sleep, anxiety,

stress, illness, ingesting, and drugs.

The normal resting adult human heart rate

ranges from 60–100 bpm.

CONT’•Bradycardia is a slow heart rate, defined

as below 60 bpm

• Tachycardia is a fast heart rate, defined

as above 100 bpm at rest.[

•When the heart is not beating in a

regular pattern, this is referred to as

an arrhythmia, These abnormalities of

heart rate sometimes, but not always,

indicate disease.

BRADYCARDIA

Bradycardia: A slow heart rate, usually

defined as less than 60 beats per

minute.

Relative bradycardia is used in explaining a

heart rate that, although not actually

below 60 BPM, is still considered too slow

for the individual's current medical

condition.

Absolute bradycardia A waking heart rate

below 40 BPM is considered absolute

bradycardia.

BRADYCARDIA IN HEALTHYDuring sleep, a slow heartbeat with

rates around 40–50 BPM is common,

and is considered normal

Highly trained athletes ( athletic

heart syndrome) know as atheletic

bradycardia or atheletic associated

cardiomegaly.

CLASSIFICATION1.Atrial

respiratory sinus arrhythmia

sinus bradycardia

Sick sinus syndrome

2.Atrioventricular nodal

An atrioventricular nodal bradycardia or

AV junction rhythm is usually caused by

the absence of the electrical impulse from

the sinus node.

3.Ventricular: A ventricular bradycardia,

also known as ventricular escape rhythm

or idioventricular rhythm.

CausesGeneral causes:

1º: Abnormal pacemaker/conduction

system (congenital or postsurgical

Injury)

infectious: Sepsis

Aging.

Heart diseases ( myocarditis,

cardiomyopathy, heart block,

Sick sinus syndrome,Mi)

Drugs( beta blocker, calcium

channel blocker, digoxin, opioid

drugs, antiarrthymias drugs)

2º: Hs & Ts:

– Hypoxia – Heart block

– H+ ions (acidosis) – Hypothermia –

Hyperkalemia, -hypoglycemia-

hypothyroidism- hypovolemia

-Trauma (head)

-Toxins

-Tension pnemothorax

-Temponate

-Thrombosis

SIGNS AND SYMPTOMS Near-fainting or

fainting (syncope)

Dizziness

Weakness

Fatigue

Shortness of

breath

Chest pains

Low BP

cyanosis

Confusion or

memory problems

Easily tiring

during physical

activity

Low heart rate

History & examination

R/O

Risk factors

use of known causative medications

age over 70 years

recent myocardial infarction

Surgery

cont’

Hypothyroidism

electrolyte disorders

infections

exposure to toxins

infiltrative diseases

sleep apnoea

Key diagnostic factors

presence of risk factors (common)

pulse rate below 50 bpm (common)

dizziness/lightheadedness (common)

syncope (common)

fatigue (common)

exercise intolerance (common)

shortness of breath (common)

cannon a-waves in jugular venous

pulse (common)

jugular venous distension (common)

Epidemiology

Impossible to give meaningful figures on

incidence and prevalence.

In most young people bradycardia is

physiological.

The incidence of pathological bradycardia

rises with age as the underlying causes

become more frequent.

DIAGNOSIS AND TEST

Electrocardiogram (ECG or EKG)

Echocardiogram

Blood tests:

CBC

Urine Examination

LFT,

Blood glucose.

Cont’

Electrolytes

Creatinine

Cardiac enzymes (troponin),CK-Mb

ABG

Chest X-ray

MANAGEMENT

Stable patients:

12 lead EKG

Consult cardiology

Unstable patients:

CABs

ACLS -Bradycardia Algorithm

Address reversible causes

(Hs & Ts)

AHA ACLS Adult

Bradycardia Algorithm

Bradyarrhythmia typically seen when the HR <50/min

Is bradyarrhythmia causing the symptoms?

The priority should be identify and treat underlying cause

Maintain patent airway: assist breathing if necessary.

Apply oxygen ( if hypoxemic; Monitor pulse oxymetry

Apply cardiac monitor; monitor blood pressure.

I/V access

12 lead ECG. If available; do not delay treatment

Is the beadyarrhythmia

causing:

Hypotension?

Altered mental status?

Signs of suck?

Ischemic chest pain?

Acute heart failure?

Yes

No

Monitor and

observe

Give atropine

If atropine in affective;

Transcutaneous pacing (OR)

Dopamine infusion (OR)

Epinephrine infusion

Consider

Expert consultation

Transcutaneous pacing

Doses/details

Atropine IV dose;

First 0.5mg bolus

Repeat every 3-5minutes;

maximum 3mg

Dopamine IV infusion

2-10mcg/kg/minute

Epinephrine IV infusion

2-10mcg/minute

Drug calculation

Dopamine

• Preparation : 200mg in 45 NS

• 1ml=4mg=4000mcg

• Dose: 5mcg – 20mcg/kg/min

• E.g. Body wt= 50kgs

• 5mcg x 50 x 60=15000

• 15000/4000= 3.75ml/hr

• (OR)

• Desired dose*body wt in kg*0.015=dose in ml

Epinephrine/Adrenaline

•Preparation: 2mg in 49ml D5

•Strength: 1ml=0.04mg=40mcg

•Dose: 0.2mcg-1.3mcg/kg/min

E.g.

0.2 x 50 x 60=600mcg

600/40=15m/hr

NURSING INTERVENTION

According to patient condition, do

planning, assessment, write nursing

diagnosis and provide care.

General nursing intervention

If ineffective air

way/unconscious; lateral recumbent or

three-quarters prone position of

the body (lateral sim’s position)

Suctioning,

place air way

Cont’Monitor with pulse oxymeter

Glasgow coma scale

Catheterization

IV access

Close monitoring of vital signs (BP,

pulse, temperature, RR)

Notify the concern physician

Reassurance to patient /attendant

cont’

ECG

Put patient on monitor

Medication as per physician advised

Informed emergency laboratory, X-ray,

people if necessary.

Assess the side affect of drugs.