Stress ECG:- Role in Arrhythmia Diagnosis

Stress ECG:- Role in Arrhythmia Diagnosis

D R S H O M U B O H O R A

A S S O C I A T E P R O F E S S O R

U N M E H T A I N S T I T U T E O F C A R D I O L O G Y A N D

R E S E A R C H C E N T R E

A H M E D A B A D

C O N S U L T A N T E L E C T R O P H Y S I O L O G I S T

V A D O D A R A

I N D I A

Introduction

Stress test TMT DSE Isoprenaline

Indications Dyspnea on exertion Fatigue on exertion Palpitations on exertion Syncope on exertion Chest pain on exertion Ectopics for prognostication Asymptomatic patients

Ectopics Sick sinus CHB congenital WPW

Which arrhythmias can come during TMT Bradycardia

Bundle branch block AV block Sinus dysfunction

Ectopics Atrial and Ventricular

Tachycardia Atrial fibrillation NSVT/VT/Torsades/V Fib Atrial tachycardia

Other ECG findings Long QT Ischemia

Precautions while interpreting arrhythmia

Linked median (Computer average) vs Raw rhythm

VPC’s may mimic VT on linked median and VPC’s may not be seen on linked median.

Raw rhythm ideal, but may have artifacts

Placement of leads is different

Hence we cannot comment on morphology of arrhythmia accurately.

Defibrillator to be present in the place

Linked medians can confuse.

Stress test with outcome being bradycardia

Case:- Dyspnea on exertion. CAG normal coronaries. Dyspnea attributed to obesity

Further continuation 2:1 conduction

Case. Fatigue on exertion but once continues then feels ok.

Stage 1. Hardly any P waves seen. Junctional

Stage 4. Could walk/run. No problems

On recovery

TMT/Stress test in assessment of bradycardia

Exercise tolerance in Sinus bradycardia and asymptomatic CHB (congenital) with narrow QRS Target heart rate achieved or not

If patient becomes symptomatic

Any sudden decrease in heart rates

Pacemaker indications Symptoms

Long pauses

Sudden decrease in rates at increasing exercise

Failure to achieve target heart rates not an indication

Stress test and atrial arrhythmia on test

Case:- Palpitations on exertion. Echo normal. Angio normal

Stage 2 Mid part

Stage 3

Stage 4 starting

Up to 6% of patients may develop atrial arrhythmia

More likely to have CAD

Atrial arrhythmias may reflect underlying left atrial enlargement and ventricular dysfunction.

Exercise-induced SVT is not a marker for latent heart disease but is a marker for AF or paroxysmal SVT

(8 times) during the follow-up period.

H E A L T H Y

R E F E R R A L P A T I E N T S W I T H C O M P L A I N T S

C A D

H E A R T F A I L U R E

Stress test and ventricular arrhythmia seen on testing

When to say it is exercise induced arrhythmia

Exercise-induced arrhythmias are defined as frequent PVCs at near-maximal or maximal exercise, or 3 consecutive PVCs or more occurring at any time.

Frequent PVCs were defined as 10 or more PVCs out of any 50 consecutive beats.

10% in 30 seconds

presence of 7 or more PVCs per minute,

Ventricular bigeminy or trigeminy,

Exercise test–induced ventricular arrhythmias were noted in 2.1% of this apparently healthy population with no CAD/SHD

With CAD 10-19% may have Ventricular arrhythmia

More common with LV dysfunction and heart failure

Case:- A patient with exercise induced symptoms, considered bronchitis

Hence made him do a TMT and ->

Diagnosis

Outflow tract ventricular tachycardia.

Options of treatment

Drugs

EPS and RFA ablation

Treated with ablation

No complaints on follow up

Case

14 year old boy with history of atypical chest pain.

? Palpitations/DOE on exertion

ECG baseline 0k.

ECHO frequent PVC however no significant finding

TMT

Basal

TMT

Stage 4 :- Slow VT, Monomorphic

Fascicular

Options

Investigations

Holter

Cardiac MRI

If elderly CAG is required

Family screening for arrhythmic cardiomyopathies

Treatment

Drugs

EPS & RFA

CASE

A 56 year old gentleman with history of exertion

induced lightheadedness with blackness in front of

eyes, breathlessness, and palpitations

k/c/o mod MR on medications for the same.

Irregular treatment. Stopped treatment for a month

? Familial retinal problem.

Clinically murmur of MR.

Right eye perception of light only.

Otherwise no s/o failure

Baseline ECG

Diagnosis

CAD ?

MR /MVP related

Idiopathic

Genetic (CPVT/ATS/Long QTS)

Investigations CAG

Cardiac MRI

Genetic testing

Therapy For polymorphic arrhythmia EPS not generally an option

Case :- 12 year old boy with seizures on exertion.

Normal ECHO. Long QT/Sinus bradycardia

Start of isoprenaline. Avoid TMT when high risk

as can fall down

Isoprenaline stress

Case

25 year old lady with exertional syncope.

Recurrent.

Family history of SCD in younger brother and similar

episodes in sister

Now pregnant.

Echo normal

Holter normal

Cannot make exercise as pregnant.

Hence isoprenaline test

ISOPRENALINE STRESS

Classical Bidirectional VT CPVT

Exercise induced Ventricular arrhythmia

Idiopathic VT Outflow tract VT

Fascicular VT

Channelopathy/Cardiomyopathy LQTS 1/ATS

CPVT

ARVC

Saini et al :- Ventricular arrhythmia is reproducible in patients known to have serious arrhythmias. Excluding infrequent single ventricular premature complexes, the reproducibility of a test with positive outcome was 76%.

Faris et al:- Subjects whose arrhythmias are reproducible may form a group more likely to develop clinical cardiovascular disease in long-term follow-up studies.

Ventricular arrhythmia in CAD

on stress test

Case

62 year old gentleman with chest pain on exertion

while doing treadmill since a week

Recent history of giddiness while doing Treadmill at

home

Active gentleman

Baseline ECG RBBB, LAD

Good LV function

At 9 minutes of exercise when the pain

started

Was immediately made to lie down and

suddenly recovered.

Admitted

CAG suggestive of triple vessel disease

Critical LAD and RCA disease

CABG done

Further need for testing.

Yes to rule out arrhythmic cardiomyopathy

Elhendy et al showed that exercise test–induced ventricular arrhythmias occurred in 146 (10%) of patients evaluated. Greater prevalence of abnormal exercise echocardiographic

findings and ischemia on exercise echocardiography, greater increase in wall motion score index with exercise, and a greater percentage of abnormal segments with exercise

Mc Henry et al showed that Patients with 3-vessel CAD and left ventricular wall motion

abnormalities were found to have a significantly greater prevalence of arrhythmia

Milanes et al showed that 4% had ventricular arrhythmia 79% of patients with ventricular fibrillation or tachycardia had an

abnormal ST response as well.

ST elevation is very arrhythmogenic while depression is not.

Recovery phase arrhythmia more dangerous

Stress test in HCM patients

Prior used for hemodynamic as well as arrhythmia

induction.

With better diagnostics like Holter and genetic

assessment, less useful.

WPW preexcitation. Stress test

Stress test to know loss of pre-excitation. Good for right sided pathways.

Basal and 4 METS

9 METS And 12 METS

Recovery

Impression

Good Effort tolerance

ST-T changes cannot be

commented on

No arrhythmia

Decrease in pre-excitation

noted

However left sided

pathway cannot be sure as

AV node also increases

conduction physiologically.

Summarizing

Stress test is integral in testing for arrhythmia and should be advised in patients with symptoms on exertion especially in young patients.

Stress test helps in diagnosis and treatment of bradycardia and tachycardia both.

Risk stratification of asymptomatic patients with VPC and SHD can be done using stress test

Appropriate precautions should be taken while doing stress test in patients with suspected arrhythmia

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FEBRUARY 17TH AND 18TH

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GUJARAT

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