Resting ST-segment depression predicts exercise-induced subendocardial ischemia in patients with hypertrophic cardiomyopathy

Kawasaki, Tatsuya; Azuma, Akihiro; Kuribayashi, Toshiro; Taniguchi, Tetsuo; Miyai, Nobuyuki; Kamitani, Takeshi; Kawasaki, Shingo; Matsubara, Hiroaki; Sugihara, Hiroki

doi:10.1016/j.ijcard.2005.03.031

Cited by 16 publications

(18 citation statements)

References 24 publications

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“…All the HCM patients underwent maximal symptomlimited exercise testing as previously described. 13 In brief, using an electrically operated bicycle ergometer, the exercise workload began with 25 W and was increased by 25 W every 2 min. The peak workload was determined at either the achievement of the maximal predicted heart rate or cessation of exertion because of excessive symptoms or systolic blood pressure of ≥250 mmHg.…”

Section: Exercise Testingmentioning

confidence: 99%

“…Summed difference score was determined to be the difference between the summed stress and rest scores. 15 We quantified SEI using software we had produced previously 2,16,17 and added some corrections to it, 13 based on the non-gated SPECT images. In brief, the LV was divided into 15 short-axis slices.…”

Section: Scintigraphymentioning

confidence: 99%

“…The SEI index was determined to be the exercise to rest ratio of the sum of 15 surface areas (Fig 1); SEI was considered present when the index was >1.07. 13 The presence or absence of transient LVCD was determined by simple visual assessment and consensus of the observers, depending on the degree to which LV enlargement occurred after exercise. 1,3,18 …”

Section: Scintigraphymentioning

confidence: 99%

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Gated Single-Photon Emission Computed Tomography Detects Subendocardial Ischemia in Hypertrophic Cardiomyopathy

Kawasaki

Akakabe

Yamano

et al. 2007

Circ J

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atients with hypertrophic cardiomyopathy (HCM) sometimes develop subendocardial ischemia (SEI) in the absence of coronary stenosis, 1-3 and in such patients it seems to be associated with either a high diastolic pressure in the left ventricle (LV) 1 or a high level of B-type natriuretic peptide, 2 possibly causing the poor prognosis. 4,5 Furthermore, SEI may be related to an abnormal blood pressure response during exercise, 3 which has been considered to be a high risk of sudden cardiac death. 6,7 Thus, assessment of SEI may be useful in risk stratification of patients with HCM.In practice, SEI is recognized as transient LV cavity dilation (LVCD) because it occurs with lactate metabolic abnormalities in the absence of significant change in LV cavity size. 1 Thus, HCM patients have been considered to have SEI if transient LVCD was identified from simple visual assessment of non-gated scintigraphic images, 1,3 but this technique may lack objectivity. Gated single-photon emission computed tomography (SPECT) has rapidly become part of routine clinical practice 8 because it enables visualization of the LV end-diastolic and end-systolic volumes, together with myocardial perfusion, through a single working process of imaging. 9 Thus, in the present study we examined whether the volumetric variables obtained by gated SPECT are useful in detecting exercise-induced SEI in patients with HCM. Methods Study PopulationWe studied 26 patients with non-obstructive HCM (21 men, 5 women; mean age 56±10 years) referred to Matsushita Memorial Hospital for rest -stress myocardial perfusion imaging in an outpatient setting. The diagnosis of HCM was based on echocardiographic demonstration of LV hypertrophy without dilation in the absence of any cardiac or systemic disorder that can cause hypertrophy. 10,11 HCM was diagnosed as non-obstructive when the pressure gradient estimated by echocardiography was <30 mmHg at rest or with provocation by the Valsalva maneuver. All the HCM patients were in normal sinus rhythm without conduction abnormalities, such as bundle branch block, or pacemaker implantation; none had valvular heart disease or coronary stenosis with a diameter reduction ≥25% on angiography. Furthermore, all the HCM patients had asymmetric septal hypertrophy with a maximum wall thickness of ≤20 mm. This selection was based on the results of a study of cardiac phantom modifying HCM with asymmetric septal hypertrophy by Nishimura et al 12 who found that the difference between the LV volume obtained by gated SPECT and the actual LV volume was within 3% when the Methods and ResultsExercise 99m Tc-tetrofosmin myocardial scintigraphy was performed in 26 HCM patients having non-obstruction and mild hypertrophy with a ventricular septal thickness ≤20 mm. SEI was quantified using software developed previously, and the results were correlated with volumetric variables obtained using Quantitative Gated SPECT software. Exercise-induced percentage change in LV end-systolic volume was higher in 9 HCM patients with SEI (25.8±3.1%) than in 17...

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Section: Exercise Testingmentioning

confidence: 99%

Section: Scintigraphymentioning

confidence: 99%

Section: Scintigraphymentioning

confidence: 99%

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Gated Single-Photon Emission Computed Tomography Detects Subendocardial Ischemia in Hypertrophic Cardiomyopathy

Kawasaki

Akakabe

Yamano

et al. 2007

Circ J

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“…On the basis of single photon emission computed tomography obtained 30 min after the injection of the tracer, we determined the presence or absence of regional septal ischemia as previously described. 13 In brief, by means of a 4-point scoring system in 16 segments of the left ventricle, myocardial ischemia was considered present when an average change from exercise to rest images was ≥1.0 in the 5 segment scores, including the ventricular septum. HCM patients sometimes develop diffuse subendocardial ischemia, involving the hypertrophied ventricular septum.…”

Section: Exercise Testingmentioning

confidence: 99%

“…[5][6][7][13][14][15][16] Thus, we examined the presence or absence of diffuse subendocardial ischemia as previously described. [13][14][15] Briefly, the left ventricle was divided into 15 short-axis slices. One hundred radii were generated at 3.6 degrees intervals from the center of the middle myocardial images of each slice.…”

Section: Exercise Testingmentioning

confidence: 99%

Septal q Wave as a Marker of Septal Ischemia in Hypertrophic Cardiomyopathy

Akakabe

Kawasaki

Yamano

et al. 2008

Circ J

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mall Q waves in the left lateral leads are often termed as septal q waves, which are considered to reflect the rightward-directed depolarization through the ventricular septum. 1,2 The response of the septal q wave to exercise has been reported to be a reliable sign of septal ischemia in patients with coronary artery disease. 3,4 Patients with hypertrophic cardiomyopathy (HCM) sometimes develop septal ischemia in the absence of coronary stenosis, but little data are available concerning the association of the septal q wave response with septal ischemia. 5-7 Thus, we examined the response of the septal q wave to septal ischemia on a short-and long-term basis in patients with HCM. MethodsThis retrospective study consisted of 29 HCM patients with asymmetric septal hypertrophy referred to the Matsushita Memorial Hospital (22 men and 7 women; age 56±10 years). The diagnosis of HCM was based on echocardiographic demonstration of ventricular septal hypertrophy with an end-diastolic thickness ≥15 mm and a nondilated left ventricle with an end-diastolic diameter ≤55 mm Circulation Journal Vol.72, June 2008 in the absence of any cardiac or systemic disorder that could cause hypertrophy, such as severe systemic hypertension or aortic stenosis. 8,9 The exclusion criteria were non-sinus rhythm, valvular heart disease or left ventricular outflow obstruction >30 mmHg on echocardiography, or abnormal Q waves in V5 and V6 defined as ≥0.04 s in width and ≥25% of the R wave in depth. All 29 HCM patients had previously undergone coronary angiography in order to exclude significant coronary artery stenosis, defined as a diameter reduction ≥25%. All medications, if any, were withdrawn for at least 5 half-lives before the exercise test; 4 patients had received -blockers or calcium channel antagonists; none of them received amiodarone. The left ventricular enddiastolic diameter was 44±5 mm, left ventricular fractional shortening 39±7%, maximum ventricular septum thickness 20±5 mm, posterior wall thickness 11±3 mm and left atrial diameter 39±4 mm on echocardiography. The New York Heart Association functional classification as assessed using the questionnaire 10 was class I in 20 patients, class II in 6 and class III in 3. Exercise TestingAll HCM patients underwent maximal symptom-limited exercise testing with Tc-99m-tetrofosmin myocardial scintigraphy as previously described. 11 The exercise workload began with 25 W and was increased by 25 W every 2 min using an electrically operated bicycle ergometer in a seated position. The exercise was discontinued at the achievement of 100% of the maximal predicted heart rate, or because of excessive leg fatigue, dyspnea, additional horizontal or down-sloping ST-segment depression ≥0.2 mV, or systolic blood pressure ≥250 mmHg. After having achieved the peak workload, all subjects had a cool-down period ≥1 min Septal q Wave as a Marker of Septal Ischemia in Hypertrophic CardiomyopathyYoshiki Akakabe, MD; Tatsuya Kawasaki, MD; Michiyo Yamano, MD; Shigeyuki Miki, MD; Tadaaki Kamitani, MD; Toshiro ...

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Reproducibility of Quantitative Estimate of Magnetocardiographic Ventricular Depolarization and Repolarization Parameters in Healthy Subjects and Patients with Coronary Artery Disease

et al. 2006

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Magnetocardiography (MCG) has been introduced as an innovative non-invasive diagnostic tool to identify various heart diseases. However, there have been little data on the reliability of MCG parameters. The purpose of this study is to examine the test-retest reliability of different diagnostic parameters derived from MCG. We investigated short-, intermediate-, and long-term reliability of nine parameters from T (max/3)-T (max) interval, and five parameters from each time point such as QRS-wave, the peak of R-, and T-wave were evaluated. Short-term reliability was tested in the youngest 20 subjects (mean age = 26.3 +/- 4.9 years) in three sessions separated by 5 min. Intermediate-term reliability was tested in the 35 subjects with coronary artery disease (CAD) (65.1 +/- 7.1 years) with two recording sessions each in the morning and afternoon, separated by more than four hours. Long-term reliability was tested in seven subjects (37.1 +/- 8.8 years) using seven daily sessions. Interclass correlation coefficients (ICC) showed that test-retest reliability was good to excellent (0.99 > or = ICC > or = 0.80) for six out of nine parameters within T (max/3)-T (max). In addition, all parameters on the peak of R-wave, T-wave, and QRS-wave integrated were good to excellent (0.99 > or = ICC > or = 0.80) except for one parameter of CAD patients showing lower ICC values under 0.7. In conclusion, our study showed that the test-retest characteristics of the studied MCG parameters are generally stable and reliable over periods of minutes to days in subjects with different age spectrums.

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Resting ST-segment depression predicts exercise-induced subendocardial ischemia in patients with hypertrophic cardiomyopathy

Cited by 16 publications

References 24 publications

Gated Single-Photon Emission Computed Tomography Detects Subendocardial Ischemia in Hypertrophic Cardiomyopathy

Gated Single-Photon Emission Computed Tomography Detects Subendocardial Ischemia in Hypertrophic Cardiomyopathy

Septal q Wave as a Marker of Septal Ischemia in Hypertrophic Cardiomyopathy

Reproducibility of Quantitative Estimate of Magnetocardiographic Ventricular Depolarization and Repolarization Parameters in Healthy Subjects and Patients with Coronary Artery Disease

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