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Effort Echocardiography
The high prevalence of heart disease has led to the development of complementary techniques of non-invasive diagnosis that are trustworthy and accessible for diagnosis and evaluation. Among them, the classic effort test on a moving carpet, although widely used, has limitations for the diagnosis of ischemia, which has led to the developing of new non-invasive methods of diagnosis. Among these, effort echocardiography (EE) is accepted as a valuable method of detecting heart disease. This form of effort is currently carried out in our centre, with the effort made on a moving carpet being the preferred form. Pharmacological stress is mainly used when one intends to assess viability, or when the patient cannot undergo effort.
Respecting the guidelines of the European Society of Cardiology (1), whenever the patient can accept effort we always firstly use stress echocardiography. Only when the patient cannot undergo effort, for example due to problems of the orthopaedic kind or when the effort test or effort echocardiogram was inconclusive due to chronotropic incompetence, do we carry out an echocardiogram through pharmacological stress.
Despite the preference we try to grant to Effort Echocardiography, pharmacological stress echocardiography is slightly more than 40% of the stress echocardiograms we carry out.
Besides the fact that effort echocardiography is imperative for us to respect the guidelines, there are reasons relative to safety that force us to grant preference whenever possible to EE. A record with 85,997 exams (2) found a rate of serious events of 1 to 6.574 EE, 1 to 1,294 stress echocardiograms with Dipiridamol and 1 event for each 557 ESD, clearly showing – even taking into account the possible influence of the reference criteria for each type of stress – the greater safety of effort. We also believe that the accessory effects of the drugs – apparently ignored in the echocardiography laboratories – should lead whenever possible to effort echocardiography to the detriment of pharmacological overload.
Methodology of Effort Echocardiography (3,4)
Effort test: The patients are questioned about their symptoms, cardiological antecedents and risk factors for heart disease. After explanation and preparation for the procedure by the cardio-pneumographical technician, a 12 derivations ECG is obtained. The effort protocol usually used in our centre is that of Bruce, with criteria for interrupting the test being: tiredness, increasing languor or dizziness, infra-imbalance of ST > than 3 mm, complex ventricular dis-rhythmias, systolic arterial pressure > than 240mmHg and/or diastolic > than 130 mmHg. The appearance of alterations in contractility, as well as its extent, do not usually constitute a criterion for the interrupting of the test.
Effort Echocardiography: An echocardiogram is carried out on the left lateral decubitus with the obtaining of images on at least four levels: long axis parasternal, short axis parasternal, apical four chambers and apical two chambers, before beginning the effort test. After the interruption of the effort test the patient is rapidly placed in left lateral and images are obtained on the same levels (in the first 90 seconds). Images are stored on a loop at rest and immediately after the end of the test. In our centre we also carry out standing echocardiograms during the effort test, with the acquisition of the cine loop at the height of the effort. For the effects of analysis we use the segmentation of ASE that divides the left ventricle into 16 segments. It is considered that there is ischemia when there are alterations in the contractility “anew”, with the appearance of zones of hipokinesia, akinesia or dyskynesia (an akinetic zone which becomes dyskinetic is not considered a sign of ischemia). Absence of hyperkinesia, particularly if localised, is also considered to be a sign of ischemia, and thus of positivity of the effort echocardiogram. The seriousness of ischemia is determined by the extent of the ischemia, assessed by the number of segments affected, but also by the precocious nature of its appearance. The longer duration of the alterations of contractility after the end of the effort also forms a sign of greater gravity.
Using the method described, we annually carry out several hundreds of effort echocardiograms in our centre. These are above all carried out for the diagnosis of ischemia and after patients had been subjected to revascularisation procedures. A significant percentage of exams is carried out in the study of valve pathology, in the evaluation of the systolic pressure of the pulmonary artery, in the study of valve prostheses, in research into intraventricular gradients in athletes (5) (Figure 1), in X syndrome (6) and in patients with hypertrophic myocardiopathy (7).
The techniques of alternative imaging, like myocardic perfusion scintigraphy, the diagnostic capacity of which is similar to stress echocardiography, should be passed over in favour of European legislation (8,9), which forces us to use complementary methods of diagnosis that do not use radiation when there are alternatives without radiation. Thus, reasons of ethical and legal nature are making stress echocardiography widely used as a preferential method for the study of our patients. The recommendations (1) and the well-being of the patients who can undergo effort testing, as well as the quantity and quality of the information obtained, are forcing us to preferentially use effort.
Carlos Cotrim
Garcia de Orta Hospital Cardiology Service
carlosadcotrim@hotmail.com
Bibliography
1. Fox K, Garcia MAA, Ardissimo D, et al. “Guidelines on the management of stable angina pectoris”. European Heart Journal, disponível em http://eurheartj.oxfordjournals.org/content/27/11/1341.full
2. Varga A, Garcia MAR, Picano E. “Safety of stress echocardiography”. American Journal of Cardiology. 2006; 98:541-543.
3. Roger VL, Pellikka PA, Oh JK, Miller FA, Sewward JB, Tajik AJ. “Stress echocardiography. Part I Exercise echocardiography: techniques, implementation, clinical aplications, and correlations”. Mayo Clinic Proceedings 1995;70:5-15.
4. Carlos Cotrim, Manuel Carrageta. “Ecocardiografia de Sobrecarga – Esforço”. Revista Portuguesa de Cardiologia, 2000;19(3):345-350.
5. Cotrim C, Almeida AG, Carrageta M. “Clinical significance of intraventricular gradient during effort in an adolescent karate player”. Cardiovascular Ultrasound, 2007,5:39
6. Cotrim C, Almeida AG, Carrageta M, “Exercise-induced intra-ventricular gradients as a frequent potential cause of myocardial ischemia in cardiac syndrome X patients”.Cardiovascular Ultrasound 2008; 6:3.
7. Picano E. “Stress echocardiography in hypertrophic cardiomyopathy”. In Picano E. ed., Stress echocardiography. 5th Edition. Springer-Verlag Berlin Heidelberg. 2009:479-486.
8. “European Commission Medical Imaging Guidelines”, 2001. incompleto
9. Euratom directive 97/43. Referência incompleta, sugiro :
COUNCIL DIRECTIVE 97/43/EURATOM of 30 June 1997 on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure…, disponivel em
http://ec.europa.eu/energy/nuclear/radioprotection/doc/legislation/9743_en.pdf
10. Picano E. Stress echocardiography in hypertrophic cardiomyopathy. In Picano E.ed. Stress echocardiography. 5th Edition. Springer-Verlag Berlin Heidelberg. 2009:479-486.
11. European Comission Medical Imaging Guidelines (2001).
12. Euratom directive 97/43.
Respecting the guidelines of the European Society of Cardiology (1), whenever the patient can accept effort we always firstly use stress echocardiography. Only when the patient cannot undergo effort, for example due to problems of the orthopaedic kind or when the effort test or effort echocardiogram was inconclusive due to chronotropic incompetence, do we carry out an echocardiogram through pharmacological stress.
Despite the preference we try to grant to Effort Echocardiography, pharmacological stress echocardiography is slightly more than 40% of the stress echocardiograms we carry out.
Besides the fact that effort echocardiography is imperative for us to respect the guidelines, there are reasons relative to safety that force us to grant preference whenever possible to EE. A record with 85,997 exams (2) found a rate of serious events of 1 to 6.574 EE, 1 to 1,294 stress echocardiograms with Dipiridamol and 1 event for each 557 ESD, clearly showing – even taking into account the possible influence of the reference criteria for each type of stress – the greater safety of effort. We also believe that the accessory effects of the drugs – apparently ignored in the echocardiography laboratories – should lead whenever possible to effort echocardiography to the detriment of pharmacological overload.
Methodology of Effort Echocardiography (3,4)
Effort test: The patients are questioned about their symptoms, cardiological antecedents and risk factors for heart disease. After explanation and preparation for the procedure by the cardio-pneumographical technician, a 12 derivations ECG is obtained. The effort protocol usually used in our centre is that of Bruce, with criteria for interrupting the test being: tiredness, increasing languor or dizziness, infra-imbalance of ST > than 3 mm, complex ventricular dis-rhythmias, systolic arterial pressure > than 240mmHg and/or diastolic > than 130 mmHg. The appearance of alterations in contractility, as well as its extent, do not usually constitute a criterion for the interrupting of the test.
Effort Echocardiography: An echocardiogram is carried out on the left lateral decubitus with the obtaining of images on at least four levels: long axis parasternal, short axis parasternal, apical four chambers and apical two chambers, before beginning the effort test. After the interruption of the effort test the patient is rapidly placed in left lateral and images are obtained on the same levels (in the first 90 seconds). Images are stored on a loop at rest and immediately after the end of the test. In our centre we also carry out standing echocardiograms during the effort test, with the acquisition of the cine loop at the height of the effort. For the effects of analysis we use the segmentation of ASE that divides the left ventricle into 16 segments. It is considered that there is ischemia when there are alterations in the contractility “anew”, with the appearance of zones of hipokinesia, akinesia or dyskynesia (an akinetic zone which becomes dyskinetic is not considered a sign of ischemia). Absence of hyperkinesia, particularly if localised, is also considered to be a sign of ischemia, and thus of positivity of the effort echocardiogram. The seriousness of ischemia is determined by the extent of the ischemia, assessed by the number of segments affected, but also by the precocious nature of its appearance. The longer duration of the alterations of contractility after the end of the effort also forms a sign of greater gravity.
Using the method described, we annually carry out several hundreds of effort echocardiograms in our centre. These are above all carried out for the diagnosis of ischemia and after patients had been subjected to revascularisation procedures. A significant percentage of exams is carried out in the study of valve pathology, in the evaluation of the systolic pressure of the pulmonary artery, in the study of valve prostheses, in research into intraventricular gradients in athletes (5) (Figure 1), in X syndrome (6) and in patients with hypertrophic myocardiopathy (7).
The techniques of alternative imaging, like myocardic perfusion scintigraphy, the diagnostic capacity of which is similar to stress echocardiography, should be passed over in favour of European legislation (8,9), which forces us to use complementary methods of diagnosis that do not use radiation when there are alternatives without radiation. Thus, reasons of ethical and legal nature are making stress echocardiography widely used as a preferential method for the study of our patients. The recommendations (1) and the well-being of the patients who can undergo effort testing, as well as the quantity and quality of the information obtained, are forcing us to preferentially use effort.
Carlos Cotrim
Garcia de Orta Hospital Cardiology Service
carlosadcotrim@hotmail.com
Bibliography
1. Fox K, Garcia MAA, Ardissimo D, et al. “Guidelines on the management of stable angina pectoris”. European Heart Journal, disponível em http://eurheartj.oxfordjournals.org/content/27/11/1341.full
2. Varga A, Garcia MAR, Picano E. “Safety of stress echocardiography”. American Journal of Cardiology. 2006; 98:541-543.
3. Roger VL, Pellikka PA, Oh JK, Miller FA, Sewward JB, Tajik AJ. “Stress echocardiography. Part I Exercise echocardiography: techniques, implementation, clinical aplications, and correlations”. Mayo Clinic Proceedings 1995;70:5-15.
4. Carlos Cotrim, Manuel Carrageta. “Ecocardiografia de Sobrecarga – Esforço”. Revista Portuguesa de Cardiologia, 2000;19(3):345-350.
5. Cotrim C, Almeida AG, Carrageta M. “Clinical significance of intraventricular gradient during effort in an adolescent karate player”. Cardiovascular Ultrasound, 2007,5:39
6. Cotrim C, Almeida AG, Carrageta M, “Exercise-induced intra-ventricular gradients as a frequent potential cause of myocardial ischemia in cardiac syndrome X patients”.Cardiovascular Ultrasound 2008; 6:3.
7. Picano E. “Stress echocardiography in hypertrophic cardiomyopathy”. In Picano E. ed., Stress echocardiography. 5th Edition. Springer-Verlag Berlin Heidelberg. 2009:479-486.
8. “European Commission Medical Imaging Guidelines”, 2001. incompleto
9. Euratom directive 97/43. Referência incompleta, sugiro :
COUNCIL DIRECTIVE 97/43/EURATOM of 30 June 1997 on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure…, disponivel em
http://ec.europa.eu/energy/nuclear/radioprotection/doc/legislation/9743_en.pdf
10. Picano E. Stress echocardiography in hypertrophic cardiomyopathy. In Picano E.ed. Stress echocardiography. 5th Edition. Springer-Verlag Berlin Heidelberg. 2009:479-486.
11. European Comission Medical Imaging Guidelines (2001).
12. Euratom directive 97/43.
