Cardiology Week 7 Summary

Question 31

Which chest pain characteristics are more likely cardiac versus non-cardiac?

Cardiac chest pain:

• Characteristics: “vise-like”, heavy, crushing, pressing, pressure, burning, aching, tightness, burning, indigestion
• Radiation: to the arm, neck or shoulder
• Associated symptoms: Nausea, vomiting, diaphoresis

Non-cardiac chest pain:

• Duration: seconds or days, as opposed to minutes or hours
• Localization: a very small area, e.g. size of the finger tip
• Precipitation: movement of the thorax or by inspiration, by palpation
• Characteristics: sharp, stabbing, pleuritic.

Question 32

What are the high-risk indicators in exercise stress testing?

1. Early positive-stage I: Mortality >5%/year
2. Strongly positive >2.5 mm ST depression
3. ST elevation >1 mm in leads without Q waves
4. Fall in systolic blood pressure (SBP) >10 mm Hg
5. Early onset ventricular arrhythmias
6. Chronotropic incompetence exercise heart rate <120/min not due to drugs
7. Prolonged Ischaemic changes in recovery,
   i.e. >2mm lasting >6 minutes in multiple leads

Question 33

What is the Duke Treadmill Score (DTS) and how it is used in exercise stress testing (EST) to help risk stratify patients who presented with acute coronary syndrome (ACS)?

The Duke Treadmill Score (DTS) is a weighted index combining treadmill exercise time using standard Bruce protocol, maximum net ST segment deviation (depression or elevation), and exercise-induced angina. It was developed to provide accurate diagnostic and prognostic information for the evaluation of patients with suspected coronary heart disease. The typical observed range of DTS is from -25 (highest risk) to +15 (lowest risk). A low DTS is actually better at excluding ischemic heart disease in women than men.

DTS = Exercise time – (5 * Max ST) – (4 * Angina Index)

Reference:
Mark DB, Hlatky MA, Harrell FE, Lee KL, Califf RM, Pryor DB. Exercise treadmill score for predicting prognosis in coronary artery disease. Ann Int Med 1987; 106:793-800.

Question 34

For mitral valve prolapse, when is surgery recommended and which symptoms should one look for?

Recommendations for surgery in patients with mitral valve prolapse (MVP) and mitral regurgitation (MR) are the same for other forms of nonischemic MR:

1. Symptomatic patients with normal left ventricular (LV) function or LV dysfunction.
   Surgery is recommended for patients with heart failure symptoms, such as dyspnea, orthopnea, paroxysmal nocturnal dyspnea, leg edema, etc.
   Among patients with very mild symptoms, surgery is recommended particularly when the valve has >90% chance of being repairable [Class I-B].
2. Asymptomatic patients with LV dysfunction.
   The timing of surgery for asymptomatic patients is controversial, but there is an agreement that MV surgery is indicated when LV dysfunction is present (LVEF 30-60% and/or LV end-systolic dimension >= 40 mm) [Class I-B].
3. Asymptomatic patients with normal LV function.
   MV repair is reasonable in experienced surgical centers for asymptomatic patients with chronic severe MR and preserved LV function [Class IIa-B]. MV surgery should also be considered for this group of patients with new onset of atrial fibrillation [Class IIa-] or pulmonary hypertension (pulmonary artery systolic pressure >50 mmHg at rest or >60 mmHg with exercise) [Class IIa-C].

Reference
Nishimur RA, et al. ACC/AHA 2014 practice guidelines for the management of patients with valvular heart disease: executive summary. JACC 2014 Jun 10;63(22):2438-88

Question 35

What is the management of patients with aortic stenosis (symptomatic and asymptomatic)?

Aortic stenosis (AS) patients who are asymptomatic should be followed clinically and by echocardiogram. The ACC/AHA guidelines [1] recommend asymptomatic AS patients to have serial echocardiographic testing with the following time intervals:

• Severe AS: every year
• Moderate AS: every two years
• Mild AS: every five years

Echocardiograms should be performed whenever there is an important change in clinical symptoms or findings.

Indications for aortic valve replacement for aortic stenosis include:

1. Angina
2. Congestive Heart Failure (CHF)
3. Syncope or presyncope
4. Episode of aborted sudden death

If a stenotic valve is not replaced, approximately 50% of patients will be dead:

1. Within 5 yrs after angina develops
2. Within 3 yrs after exertional syncope develops
3. Within 2 yrs after heart failure develops

Symptoms are usually associated with:

• aortic valve area (AVA) >0.8 cm²
• and/or transvalvular mean gradient >50 mmHg.

Patients often exhibited symptomatic improvement and increased in survival after AVR.

Reference:
Nishimur RA, et al. ACC/AHA 2014 practice guidelines for the management of patients with valvular heart disease: executive summary. JACC 2014 Jun 10;63(22):2438-88