approach to chest pain. history “when it comes to chest pain, if you aren’t confident with your...

Approach to Chest Pain

History

“When it comes to chest pain, if you aren’t confident with your diagnosis after your history, take it again”

Dr. M. Gamble

OLD CARS

OLD CARS

• O: onset

• L: location

• D: duration

• C: character

• A: associated/aggravating/alleviating

• R: radiation

• S: sex

Are cardiac risk factors useful in evaluating the risk of ACS?

• Registry Data• 10 806 ED visits for ACS (good definitions)• Risk factors:

– Smoking– DM– HTN– Dislipidemia– Family History

Results

ROC

Conclusions

• In patients over 40, cardiac risk factor burden is of limited clinical value in the diagnosis of ACS

• In patients under 40, cardiac RF useful if there are none (-LR 0.17) or if there are 4 or more (+LR 7.39)

How useful are clinical features in the diagnosis of acute, undifferentiated chest pain?

• Prospective study of 893 pts presenting to ED with CP• Tested the power of clinical features to predict AMI

(WHO criteria) and ACS (cardiac testing, AMI, death, or revascularization within 6 months).

Conclusions:1. AMI:

– Exertional pain (LR: 2.35)– Pain radiating to shoulder or both arms (LR: 4.07)– Chest wall tenderness (LR: 0.3)

• ACS:– Exertional Pain (LR: 2.06)– Pain radiating to shoulder or left arm, or both arms

(LR: 1.62)

• Location of the pain, quality and presence of N/V or diaphoresis were not predictive

Right arm involvement?Berger, J. 1990. J Intern Med. 277(3)

• Prospective study of 278 ED pts with CP– 100 MI– 47 UA– 25 SA– 106 non-coronary disease

• Most specific feature for MI:– Right arm radiation

• 51 pts with right arm radiation• 47 had coronary disease (41 MI’s)

Question 3

What is the predictive and prognostic value of the ECG in patients with ACS?

Definitions

• Non-specific ST and T wave changes– ST segment depression or elevation of < 1mm

with or without an abnormal T wave– T wave may have altered morphology and/or

blunted, flattened, or biphasic configuration without inversion or hyperacuity

• Normal– Absence of NSSTTW, AV block, intraventricular

conduction delay, repolarization changes, and rhythms other than NSR

ECG Findings in ACS

• CP in the ED with a normal ECG:– 1% final diagnosis of AMI– 4% final diagnosis of UA

• Another study – typical chest pain pts:– 3% final diagnosis of AMI

• NSSTW findings:– 3-4% of AMI pts– 20% of NSTEMI/UA pts

• Therefore, of all patients with ACS, one fifth will show a normal or non-specific ECG in the ED

ECG Changes

• Of 202 chest pain patients presenting to the ED with STE, 15% had an AMI

• LVH was the most common cause of STE (25%), followed by LBBB (15%) and AMI (15%)

• 12% had BER, 5% had RBBB, and 5% had nonspecific BBB

• Other less common diagnoses were LVA, pericarditis, and paced rhythm

Prognostic Value of Admission ECG in ACS

• GUSTO-IIb trial data

• Over 12,000 patients who had ACS confirmed on ECG

• 22% had T wave inversion, 28% had STE, 35% had STD, and 15% had a combination of the above

• 30 day incidence of death or MI:

– TWI: 5.5%

– STE: 9.4%

– STD: 10.5%

– STE & STD: 12.4%

ECG Pearls

• 50% of patients with AMI will have a clearly diagnostic ECG at presentation (STE or STD)

• ST segment elevation identifies those who benefit from reperfusion therapy (lytics)

• Mortality increases with the number of leads showing STE

• RV infarcts complicate 40% of inferior AMIs

What is the utility of cardiac biomarkers in diagnosing ACS?

2 h 4h 6h 8h 10h 12h

TroponinSensitivity

20 45 75 82 95 98

Goodacre et al. How Useful are Clinical Features in the Diagnosis of Acute, Undifferentiated Chest Pain? Academic Emergency Medicine, vol. 9, no. 3, 2002.

Feature OR CI pRadiation to Shoulder 5.7 1.5-21.4 sig

Radiation to Both Arms 4.9 1.3-19.4 sigBurning/Indigestion 3.4 0.4-31.0 NSNausea/Vomiting 1.3 0.5-3.3 NSExertional Pain 3.3 1.3-8.4 sig

Tender Chest Wall 0.2 0.05-0.97 sig

Features Predictive of AMI:

Thanks Adam

Goodacre et al. How Useful are Clinical Features in the Diagnosis of Acute, Undifferentiated Chest Pain? Academic Emergency Medicine, vol. 9, no. 3, 2002.

Feature OR CI pRadiation to shoulder 5.2 2.0-13.4 sigRadiation to left arm 2.1 1.0-4.4 sig

Radiation to both arms 4.8 1.8-13.2 sigExertional pain 2.4 1.3-4.5 sigPleuritic pain 0.6 0.2-1.7 NS

Tender chest wall 0.6 0.3-1.2 NS

Features Predictive of ACS:

Thanks Adam