Dobutamine Stress Testing as a Diagnostic Tool for Evaluation of Myocardial Contractile Reserve in Asymptomatic or Mildly Symptomatic Patients With Dilated Cardiomyopathy
Masakazu Kobayashi, MD*,
Hideo Izawa, MD, PhD*,
Xian Wu Cheng, MD, PhD ,
Hiroyuki Asano, MD*,
Akihiro Hirashiki, MD, PhD*,
Kazumasa Unno, MD*,
Satoru Ohshima, MD*,
Takashi Yamada, MD*,
Yosuke Murase, MD, PhD*,
Tomoko S. Kato, MD, PhD*,
Koji Obata, PhD ,
Akiko Noda, PhD ,
Takao Nishizawa, MD, PhD*,
Satoshi Isobe, MD, PhD*,
Kohzo Nagata, MD, PhD¶,
Tatsuaki Matsubara, MD, PhD,
Toyoaki Murohara, MD, PhD*,
Mitsuhiro Yokota, MD, PhD, FACC||,*
* Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
Cardiovascular Research Medicine, Nagoya University School of Medicine, Nagoya, Japan
Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
Department of Internal Medicine, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
|| Department of Genome Science, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan
¶ Nagoya University School of Health Sciences, Nagoya, Japan
View larger version (10K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2 Comparison of Plasma NE Levels Among the 3 Patient Groups
Plasma norepinephrine (NE) levels measured at baseline were significantly higher in group IIa and in group IIb compared with that in group I. Data for individual subjects and the corresponding mean ± SD values are shown.
|
|
View larger version (10K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3 Comparison of the Delayed H/M Ratio in [123I]MIBG Scintigraphy Among the 3 Patient Groups
We determined the heart/mediastinum (H/M) count ratio from the delayed planer [123I]metaiodobenzylguanidine (MIBG) image. The delayed H/M ratio was significantly lower in group IIa and in group IIb compared with that in group I. Data for individual subjects and the corresponding mean ± SD values are shown.
|
|
View larger version (28K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4 A Representative Case of Group I
This patient was a 43-year-old woman in New York Heart Association functional class I, and she had an LVEF of 43% and a plasma norepinephrine level of 328 pg/ml. (A) Mildly reduced myocardial uptake was observed, and the delayed H/M ratio was 2.2. (B) The relationship between dobutamine infusion rate and LV dP/dtmax of this patient is shown. The LV dP/dtmax at baseline and at a dobutamine infusion rate of 10 µg kg–1 min–1 were 986 and 2,415 mm Hg/s, respectively ( LV dP/dtmax = 145%). Abbreviations as in Figures 1 and 3.
|
|
View larger version (29K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5 A Representative Case of Group IIa
This patient was a 58-year-old woman in New York Heart Association functional class II, and she had an LVEF of 42% and a plasma norepinephrine level of 1,200 pg/ml. (A) Increased lung uptake and severely reduced myocardial uptake are observed, and the delayed H/M ratio was 1.3. (B) The relationship between dobutamine infusion rate and LV dP/dtmax of this patient is shown. The LV dP/dtmax at baseline and at a dobutamine infusion rate of 10 µg kg–1 min–1 were 1,089 and 1,791 mm Hg/s, respectively (LV dP/dtmax = 64%). Abbreviations as in Figures 1 and 3.
|
|
|
100% and LVEF >25%; and group IIb (brown triangles, n = 11),