The dicrotic notch (DN) is a negative wave that appears just after the peak systolic pressure, and the DN has been reported to reflect closure of the aortic valve and the start of the diastolic phase. However, factors related to the DN of the common carotid artery (CCA) remain unclear. A study involving 37 subjects was conducted to evaluate factors affecting the DN of the carotid artery using carotid ultrasonography. The velocity from the bottom of the DN to the first peak in the diastolic phase was measured. The associations of DN values with sonographic parameters such as peak systolic velocity (PSV) and plaque score (PS) and clinical factors, including age and the presence of hypertension, dyslipidemia, and diabetes mellitus, were assessed. DN values tended to be lower in patients with a stroke history (median 7.3 cm/sec, range 4.2-28.5 cm/sec) than in patients without a stroke history (median 12.4 cm/sec, range 6.0-26.8 cm/sec). Patients with dyslipidemia tended to have decreased DN values compared with those without dyslipidemia. DN values were negatively correlated with age and PS, and were positively correlated with PSV. Further studies are needed to clarify the clinical significance of the DN of the CCA.
The aim of this study is to evaluate factors related to the pulse Doppler waveform of the common carotid artery (CCA) in the systolic phase. Sixteen consecutive subjects who underwent carotid ultrasonography and transthoracic echocardiography (TTE) were included. Peak systolic velocity (PSV), time-averaged maximum velocity (TAMV), end diastolic velocity (EDV), pulsatility index (PI), resistance index (RI), the diameters of the CCA and internal carotid artery (ICA), the presence of ICA stenosis at the origin as well as the angle between the ICA and CCA were measured. The pulse Doppler waveforms of the CCA were categorized into the following three patterns: type A (15 vessels, bimodal peaks with the latter being small), type B (9 vessels, bimodal peaks with both peaks being equal or higher) and type C (8 vessels, a uninomodal peak). Valvular heart disease and left ventricular ejection fraction were evaluated by TTE. The frequency of aortic regurgitation, EDV, TAMV and RI were different among the groups (p < 0.05, p < 0.1, p < 0.05, p < 0.1, respectively). In multivariate analysis, using Type A as the reference group, no parameters were associated with type B, but TAMV and RI were significantly associated with type C. We conclude that the TAMV and RI of CCA might contribute to changes in the CCA waveforms.
Purpose: The objective of this study was to assess early recanalization rates following intravenous recombinant tissue plasminogen activator (rt-PA) therapy by magnetic resonance angiography (MRA) or digital subtraction angiography (DSA) in patients with acute ischemic stroke in order to plan a clinical investigation for a newly developed sonothrombolysis system. Methods: We retrospectively enrolled consecutive patients with acute ischemic stroke who were treated with intravenous rt-PA. Early recanalization within 2 hours and 24 hours after the initiation of rt-PA was evaluated by modified Mori grade on follow-up MRA or Thrombolysis in Cerebral Infarction (TICI) score on follow-up DSA. Results: A total of 384 patients were enrolled (243 men, age 74 ± 13 years) in the study. Patients were subdivided into groups based upon arterial location as follows: 63 patients in the internal carotid artery (ICA), 181 in the middle cerebral artery (MCA [M1 and M2 segments]), 5 in the anterior cerebral artery (ACA), and 14 in the posterior cerebral artery (PCA). Among patients with major artery occlusion (ICA, MCA, ACA, or PCA), the rates of recanalization were 37.2% within 2 hours and 57.4% within 24 hours; 8 of 232 patients (3.4%) had symptomatic intracranial hemorrhage within the initial 36 hours, and 76 of 225 patients (33.8%) had a favorable functional outcome (modified Rankin Scale (mRS) 0-1) at 3 months. Conclusions: We assessed early recanalization rates and clinical outcome following intravenous rt-PA therapy.
Objective: The cause of acute ischemic stroke is unknown in many patients at the time of admission. We aimed to determine the current status of diagnostic test performance and definitive diagnosis at hospital discharge in patients with embolic strokes of unknown source on admission. Methods: Between July 2012 and June 2013, 623 patients with acute ischemic stroke were admitted to our hospital within 7 days from onset. Among them, patients with non-lacunar strokes, excluding those with occlusive atherosclerosis or high-risk sources of cardioembolism, were enrolled. We evaluated the execution rates of examinations and their findings as well as the definitive stroke subtypes of patients at discharge. Results: In total, 147 patients (59 women; mean age: 73 ± 14 years) were enrolled. The execution rate of each examination was: electrocardiogram monitoring in 100%; Holter electrocardiogram in 76%; transthoracic echocardiography in 72%; and transesophageal echocardiography in 68% of patients. Paroxysmal atrial fibrillation and patent foramen ovale were detected in 20% and 46% of patients, respectively, representing the majority of the embolic sources. Stroke subtypes were determined to be: cardioembolism in 54% (High-risk 24%, Medium-risk 30%); Large-artery atherosclerosis in 9%; other determined etiology in 4%; and undetermined etiology in 33% of patients at discharge. Conclusions: Cardioembolic stroke was diagnosed in one-half of patients with embolic stroke, whereas an embolic source could not be detected in one-third of patients. Embolic stroke of undetermined source (ESUS) was found in 13% of total ischemic strokes at discharge. Further studies are needed to investigate the diagnostic characteristics of ESUS.
An 85-year-old woman came to our hospital due to an inability to live independently from a decline in her activities of daily living. Neurologically, she showed no focal signs, but multiple acute ischemic lesions were evident in the posterior circulation on magnetic resonance imaging. Occlusion of the right intracranial vertebral artery (VA) and stenosis of the left intracranial VA were detected on magnetic resonance angiography (MRA). Carotid duplex ultrasonography (CUS) showed a flow pattern with occlusion of the right VA before the branching of the posterior inferior cerebellar artery. Based upon antegrade flow in the right intracranial VA as evaluated on transcranial color flow imaging, the distal VA territory might have been maintained via collateral flow. With antiplatelet therapy and intravenous injection of argatroban, the patient’s activity gradually improved to the same level as before admission. Recanalization of the right VA was seen on MRA and CUS at 14 days after admission. Reduced cerebellar blood flow due to VA occlusion was thought to be associated with the mechanism affecting her activity levels. Follow-up ultrasonography was useful for evaluating changes in intracranial hemodynamics in this patient who demonstrated neurological improvement.
An 80-year-old man was admitted to our hospital with disturbance of consciousness, and complained of bilateral aggravated visual acuity 10 days after admission. Carotid Doppler ultrasonography showed stenosis of bilateral cervical internal carotid arteries. Transcranial color flow imaging demonstrated reversed flow at markedly decreased velocities in the left ophthalmic artery (OA) and bilateral middle cerebral arteries (MCA). Ocular ischemic syndrome was diagnosed. Percutaneous carotid artery stenting (CAS) was performed for bilateral carotid artery stenosis. After this procedure, stenosis of bilateral carotid arteries improved and OA flow became antegrade. Blood flow velocity in the OA and MCA was increased. However, visual acuity remained unimproved. Neurosonological examination is noninvasive and useful for evaluating cerebral blood flow and ocular ischemia, particularly when clinical improvement is insufficient after CAS.