Angina occurs relatively late following the onset of ischaemia: after the development of left ventricular dysfunction and electrocardiographic changes. Most ischaemic episodes are not severe enough or long enough to fully stimulate the anginal pain pathway. They are therefore clinically silent. More severe and prolonged episodes of ischaemia can also be silent. Pain thresholds vary between individuals and this is due to differences in gating mechanisms at the level of the thalamus. This gating appears to be modulated by levels of endogenous endorphins, among other mechanisms. This seems to have a relation to personality type. Silent ischemia is especially common in diabetic patients, and is often due to cardiac autonomic neuropathy.
O'Sullivan JJ , Conroy RM, MacDonald K. et al. Silent ischaemia in diabetic men with autonomic neuropathy. Br Heart J1991;66:313-5.
8.
Niakan E., Harati Y., Rolak LA et al. Silent myocardial infarction and diabetic cardiovascular autonomic neuropathy. Arch Intern Med1986;146:2229-30.
9.
Faerman I., Faccio E., Milei J. et al. Autonomic neuropathy and painless myocardial infarction in diabetic patients: histological evidence of their relationship. Diabetes1977;26:1147-58.
10.
Duchen LW, Anjorin A., Watkins PJ et al. Pathology of autonomic neuropathy in diabetes mellitus. Ann Intern Med1980;92:301-3.
11.
Droste C., Roskamm H.Experimental pain measurements in patients with asymptomatic myocardial ischaemia . J Am Coll Cardiol1983;81:164-72.
12.
Sheps DS, McMahon RP, Light KC et al. Low hot pain threshold predicts shorter time to exercise-induced angina: results from the psychosociological investigators of myocardial ischaemia (PIMI) study. J Am Coll Cardiol1999;33:1855-62.
13.
Sheps DS, Maixner W., Hinderliter ALMechanisms of pain perception in patients with silent myocardial ischemia . Am Heart J1990; 119:983-7.
14.
Sheps DS, Adams KF, Hinderliter A. et al. Endorphins are related to pain perception in coronary artery disease. Am J Cardiol1987;59:523-7.
15.
Krittayaphong R., Light KC, Golden RN et al. Relationship among depression scores, beta-endorphin, and angina pectoris during exercise in patients with coronary artery disease. Clin J Pain1996;12:126-33.
16.
Falcone C., Guasti L., Ochan M. et al. Beta-endorphins during coronary angioplasty in patients with silent or symptomatic myocardial ischemia. J Am Coll Cardiol1993;22:1614-20.
17.
Oldroyd KG, Harvey K., Gray CE et al. Beta-endorphin release in patients after spontaneous and provoked acute myocardial ischaemia. Br Heart J1992 ;67:230-5.
18.
Mazzone A., Cusa C., Mazzucchelli I. et al. Increased production of inflammatory cytokines in patients with silent myocardial ischemia. J Am Coll Cardiol2001;38:1895-901.
19.
Siegel WC, Mark DB, Hlatky MA et al. Clinical correlates and prognostic significance of type A behavior and silent myocardial ischemia on the treadmill. Am J Cardiol1989;64:1280-3.
20.
Alam M., Khaja F., Brymer J. et al. Echocardiographic evaluation of left ventricular function during coronary angioplasty. Am J Cardiol1986;57:20-5.
21.
Hauser AM, Vellappillil G., Ramos RG et al. Sequence of mechanical, electrocardiographic and clinical effects or repeated coronary artery occlusion in human beings:echocardiographic observations during angioplasty. J Am Cardiol Clin1985 ;5:193-7.
22.
McLaurin LP , Rolett EL, Grossman W.Impaired left ventricular relaxation during pacing-induced ischaemia. Am J Cardiol1973 ;32: 751-7.
23.
Iskandrian AS, Bernis CE, Hakki AH et al. Ventricular systolic and diastolic impairment during pacing-induced myocardial ischaemia in coronary artery disease: simultaneous haemodynamic, electrocardiographic and radionuclide angiographic evaluation. Am Heart J1986;112:382-91.
24.
Chierchia S. , Brunelli C., Simonetti I. et al. Sequence of events in angina at rest: primary reduction in coronary flow. Circulation1980;61:759-68.
25.
Hauser AM, Gangadharan V., Ramos R. et al. Sequence of mechanical, electrocardiographic and clinical effects of repeated coronary artery occlusion in human beings: echocardiographic observations during coronary angioplasty. J Am Coll Cardiol1985;5:193-7.
26.
Dweck M., Campbell I., Miller D., Francis M.Clinical aspects of silent myocardial ischaemia: with particular reference to diabetes mellitus. Br J Diabetes Vasc Dis2009;9:110-116.
