Biomedical subjects

Pedram Kazemi-Esfarjani

Publications and source records attributed to Pedram Kazemi-Esfarjani.

2 recordsLinked to original sources

PubMed2002

A forearm exercise screening test for mitochondrial myopathy.

BACKGROUND: The authors hypothesized that impaired oxygen extraction in mitochondrial myopathy (MM) results in a high oxygen saturation in venous effluent blood from working muscle and that this phenomenon can be used as a diagnostic tool for MM. METHODS: Twelve patients with MM, 10 patients with muscular dystrophy, and 12 healthy subjects were studied. All subjects performed intermittent static handgrip exercise (1/2 Hz) at 40% of maximal voluntary contraction (MVC) for 3 minutes. Cubital venous oxygen saturation and brachial artery flow were measured in the exercised arm. RESULTS: Exercise-induced venous oxygen desaturation was smaller in patients with MM (Delta - 7 +/- 5%) than in subjects with muscular dystrophy (Delta - 38 +/- 2%; p = 0.00001) and healthy subjects (Delta - 43 +/- 2%; p = 0.0000002). MVC and exercise blood flow were similar in patients with MM (18 +/- 3 kg; 436 +/- 65 mL/min) and patients with muscular dystrophy (15 +/- 3 kg; 460 +/- 85 mL/min), but were higher in healthy subjects (32 +/- 4 kg; 630 +/- 58 mL/min; p < 0.03). In seven patients with MM and seven patients with McArdle disease, studied with a slightly different protocol, exercise-induced oxygen desaturation was also impaired in MM (Delta - +/- 5%) compared with McArdle disease (Delta - 26 +/- 3%; p = 0.007). CONCLUSION: Oxygen desaturation in venous blood from exercising muscle is markedly lower in patients with mitochondrial myopathy than in subjects with other muscle diseases and healthy subjects, suggesting that a forearm exercise test can be a diagnostic screening tool for mitochondrial myopathy.

Adult↗

PubMed2002

A nonischemic forearm exercise test for McArdle disease.

Ischemic forearm exercise invariably causes muscle cramps and pain in patients with glycolytic defects. We investigated an alternative diagnostic exercise test that may be better tolerated. Nine patients with McArdle disease, one with the partial glycolytic defect phosphoglycerate mutase deficiency, and nine matched, healthy subjects performed the classic ischemic forearm protocol and an identical protocol without ischemia. Blood was sampled in the median cubital vein of the exercised arm. Plasma lactate level increased similarly in healthy subjects during ischemic (Delta5.1 +/- 0.7mmol L(-1)) and non-ischemic (Delta4.4 +/- 0.3) tests and decreased similarly in McArdle patients (Delta-0.10 +/- 0.02 vs Delta-0.40 +/- 0.10mmol L(-1)). Postexercise peak lactate to ammonia ratios clearly separated patients and healthy controls in ischemic (McArdle, 4 +/- 2 [range, 1-12]; partial glycolytic defect phosphoglycerate mutase deficiency, 6; healthy, 33 +/- 4 [range, 17-56]) and non-ischemic (McArdle, 5 +/- 1 [range, 1-10]; partial glycolytic defect phosphoglycerate mutase deficiency, 5; healthy, 42 +/- 3 [range, 35-56]) protocols. Similar differences in lactate to ammonia ratio between patients and healthy subjects were observed in two other work protocols using intermittent handgrip contraction at 50% and static handgrip exercise at 30% of maximal voluntary contraction force. All patients developed pain and cramps during the ischemic test, and four had to abort the test prematurely. No patient experienced cramps in the non-ischemic test, and all completed the test. The findings indicate that the diagnostic ischemic forearm test for glycolytic disorders should be replaced by an aerobic forearm test.

Adult↗