Remarkable advances have been made in the treatment of cardiovascular diseases (CVD), however, CVD still accounts for the most deaths in industrialized nations. Ischemic heart disease (IHD) can lead to acute coronary syndrome (ACS) (myocardial infarction [MI]). The standard of care is reperfusion therapy followed by pharmacological intervention to attenuate clinical symptoms related to the MI. While survival from MI has dramatically increased with the implementation of reperfusion therapy, these individuals will inevitably suffer progressive pathological remodeling leaving them predispose to develop heart failure (HF). HF is a clinical syndrome defined as the impairment of the heart to maintain organ perfusion at rest and/or during times of exertion (i.e. exercise intolerance). Clinically, this is accompanied by dyspnea, pulmonary or splanchnic congestion and peripheral edema. Physiologically, there is neurohormal activation through the classical β–adrenergic and PKA–dependent signalin / Physiology

Background and aims Heart failure (HF) is a major cause of serious morbidity and death in the population and one of the leading medical causes of hospitalization among people older than 60 years. The aim of this thesis was to describe how to create and how to analyze a Heart Failure Registry with emphasis on Anemia and Quality of Life. (Paper I) We described the creation of the Swedish Heart Failure Registry (SwedeHF) as an instrument, which may help to optimize the handling of HF patients and show how the registry can be used to improve the management of patients with HF. (Paper II) In order to show how to analyze a HF registry we investigated the prevalence of anemia, its predictors, and its association with mortality and morbidity in a large cohort of unselected patients with HFrEF included in the SwedeHF, and to explore if there are subgroups of HF patients identifying high--‐risk patients in need of treatment. (Paper III) In order to show another way of analyzing a HF registry we assessed the prevalence of, associations with, and prognostic impact of anemia in patients with HFmrEF and HFpEF. (Paper IV) Finally we examined the usefulness of EQ--‐ 5D as a measure of patient--‐reported outcomes among HF patients using different analytical models and data from the SwedeHF, and comparing results about HRQoL for patients with HFpEF and HFrEF. Methods An observational study based on the SwedeHF database, consisting of about 70 variables, was undertaken to describe how a registry is created and can be used (Paper I). One comorbidity (anemia) was applied to different types of HF patients, HFrEF (EF <40%) (II) and HFmrEF (EF 40--‐49% ) or HFpEF (> 50%) (III) analyzing the data with different statistical methods. The usefulness of EQ--‐5D as measure of patient--‐ reported outcomes was studied and the results about HRQoL were compared for patients with HFpEF and HFrEF (IV). Results In the first paper (Paper I) we showed how to create a HF registry and presented some characteristics of the patients included, however not adjusted since this was not the purpose of the study. In the second paper (Paper II) we studied anemia in patients with HFrEF and found that the prevalence of anemia in HFrEF were 34 % and the most important independent predictors were higher age, male gender and renal dysfunction. One--‐year survival was 75 % with anemia vs. 81 % without (p<0,001). In the matched cohort after propensity score the hazard ratio associated with anemia was for all--‐cause death 1.34. Anemia was associated with greater risk with lower age, male gender, EF 30--‐39%, and NYHA--‐class I--‐II. In the third paper (Paper III) we studied anemia in other types of HF patients and found that the prevalence in the overall cohort in patients with EF > 40% was 42 %, in HFmrEF 38 % and in HFpEF (45%). Independent associations with anemia were HFpEF, male sex, higher age, worse New York Heart Association class and renal function, systolic blood pressure <100 mmHg, heart rate ≥70 bpm, diabetes, and absence of atrial fibrillation. One--‐year survival with vs. without anemia was 74% vs. 89% in HFmrEF and 71% vs. 84% in HFpEF (p<0.001 for all). Thus very similar results in paper II and III but in different types of HF patients. In the fourth paper (Paper IV) we studied the usefulness of EQ--‐5D in two groups of patients with HF (HFpEF and HFrEF)) and found that the mean EQ--‐5D index showed small reductions in both groups at follow--‐up. The patients in the HFpEF group reported worsening in all five dimensions, while those in the HFrEF group reported worsening in only three. The Paretian classification showed that 24% of the patients in the HFpEF group and 34% of those in the HFrEF group reported overall improvement while 43% and 39% reported overall worsening. Multiple logistic regressions showed that treatment in a cardiology clinic affected outcome in the HFrEF group but not in the HFpEF group (Paper IV). Conclusions The SwedeHF is a valuable tool for improving the management of patients with HF, since it enables participating centers to focus on their own potential for improving diagnoses and medical treatment, through the online reports (Paper I). Anemia is associated with higher age, male gender and renal dysfunction and increased risk of mortality and morbidity (II, III). The influence of anemia on mortality was significantly greater in younger patients in men and in those with more stable HF (Paper II, III). The usefulness of EQ--‐5D is dependent on the analytical method used. While the index showed minor differences between groups, analyses of specific dimensions showed different patterns of change in the two groups of patients (HFpEF and HFrEF). The Paretian classification identified subgroups that improved or worsened, and can therefore help to identify needs for improvement in health services (Paper IV).

Résumé: Mise en contexte : Les infarctus antérieurs avec élévation du segment ST (IMAEST) causent fréquemment une dysfonction ventriculaire gauche. Une diminution de la fraction d’éjection du ventricule gauche (FeVG) est associée à une augmentation du risque d’accident vasculaire cérébral (AVC). Les lignes directrices recommandaient jusqu’à récemment (Classe I, niveau d’évidence C) l’anticoagulation des patients qui, après un IMAEST, étaient jugés à haut risque d’embolie systémique tels que les infarctus étendus ou de la paroi antérieure. Généralement, ces patients reçoivent une anticoagulation d’une durée de trois mois en combinaison avec une double thérapie antiplaquettaire pour au moins quatre semaines. Si les anomalies régionales de la contractilité se normalisaient avant trois mois, la durée de l’anticoagulation pourrait potentiellement être écourtée. La cinétique de récupération des infarctus antérieurs revascularisés par angioplastie primaire est mal décrite. Objectif : Chez des patients ayant subi un IMAEST de la paroi antérieure revascularisés par angioplastie primaire, évaluer si la FeVG et la récupération de l’akinésie antérieure et apicale est différente à un mois et trois mois post infarctus. Méthode : De façon prospective, nous avons recruté 42 patients présentant une FEVG de 45% ou moins et une akinésie de la paroi antérieure ou apicale lors de l’échocardiographie réalisée 48 heures post IMAEST. Des échocardiographies étaient obtenues à un mois et trois mois post IMAEST. Chaque échocardiographie était interprétée par deux cardiologues indépendants à l’aveugle des données cliniques. Résultats : Lorsque comparée à la FeVG à 48 heures post IMAEST, la FeVG à un mois s’était déjà améliorée de façon significative (38% à 42%, p=0.03). Il n’y avait pas d’amélioration significative supplémentaire entre un mois et trois mois (42% à 44%, p=NS). La dynamique des segments apicaux et antérieurs s’améliorait de façon significative entre 48 heures et un mois, mais aussi entre un mois et trois mois. Conclusion : Vu l’amélioration significative de la FeVG et de l’akinésie antérieure et apicale à un mois post IMAEST, il pourrait être justifié de ré-évaluer la FeVG plus précocement chez les patients anticoagulés pour cette indication afin de minimiser la durée de l’anticoagulation et le risque de saignement qui y est associé. / Abstract: Background: Anterior ST-elevation myocardial infarction (STEMI) frequently causes left ventricular dysfunction. Worsening left ventricular ejection fraction (LVEF) is associated a higher stroke rate. Prior guidelines recommended anticoagulation for patients after STEMI who are at high risk for systemic emboli and specified that large or anterior myocardial infarctions (MI) are part of that group (Class I, level of Evidence C). The 2013 Guidelines made it a Class IIB recommendation and restricted the recommendation to those with anterior or apical akinesia and dyskinesia. These patients are usually given three months of anticoagulation. If the regional wall motion abnormalities were to normalize earlier, the duration of anticoagulation could be shortened. However, the kinetics of recovery after an anterior MI revascularized with primary percutaneous intervention are not well described. Objective: To evaluate if LVEF and apical and anterior akinesia recuperation is different at one month and three months after STEMI in patients treated with primary percutaneous angioplasty. Methods: We prospectively recruited 42 patients who had a LVEF of 45% or less and apical or anterior akinesia on echocardiography at 48 hours post STEMI. Echocardiography was repeated one month and three months post STEMI. Each echocardiogram was interpreted by two different cardiologists who were blinded to clinical information. Results: When compared to 48 hours post STEMI, LVEF at one month had already improved significantly (38% to 42%, p=0.03) and there was no further significant improvement at three months (44%, p=NS). Anterior and apical akinesia decreased significantly between the 48 hours and one month echocardiograms, but also between one month and three months. Conclusion: Given that LVEF and anterior/apical akinesia improve significantly within the first post STEMI month, it may be worth re-evaluating the LVEF earlier in patients in whom the decision was made to start anticoagulation for that indication in order to minimize the duration of anti-coagulation and the associated bleeding risk.

On estime qu'approximativement 20 millions de personnes dans le monde souffrent d'insuffisance cardiaque et la prévalence de cette pathologie ne cesse d'augmenter avec le vieillissement croissant de la population. L'évaluation de la fonction ventriculaire gauche par la mesure de la fraction d'éjection permet en fait de distinguer deux populations distinctes de patients insuffisants cardiaques : l'une avec et l'autre sans altération de la fraction d'éjection, encore dénommées respectivement Heart Failure with Reduced Ejection Fraction (IC-FEr) et Heart Failure with Preserved Ejection Fraction (IC-FEp). On ne sait pas aujourd'hui si ces deux entités représentent deux pathologies distinctes ou, au contraire, deux entités intimement liées. L'IC-FEp est actuellement observée chez environ 40 à 50% des patients présentant une insuffisance cardiaque et son évolution est semblable à celle des patients IC-FEr.Le concept d'IC-FEp soulève toutefois des difficultés conceptuelles : d'une part car la notion d'une fraction d'éjection préservée implique la connaissance de sa valeur de base et d'autre part, les valeurs dites "normales" de la fraction d'éjection sont encore à établir. Par ailleurs, la vision mécanique du cœur comme une pompe hémodynamique ou musculaire conditionne la compréhension de la physiopathologie de la IF-FEp.Dans ce contexte, nous avons mis au point un modèle porcin de dysfonction diastolique avec éjection préservée secondaire à une hypertension artérielle induite par une perfusion continue d'angiotensine II pendant 28 jours. Dans ces conditions, nous avons démontré une altération de la fonction ventriculaire gauche alors même que l'éjection était préservée. Ceci était objectivé par 1) une augmentation paradoxale des durées relatives de contraction et de relaxation isovolumiques, 2) des réponses inappropriées des phases isovolumiques du cycle cardiaque à des augmentations de la fréquence et de l'inotropisme cardiaques et 3) une étroite relation entre ces deux phases isovolumiques (couplage contraction-relaxation). L'inadéquation entre les niveaux de fréquence cardiaque et des phases isovolumiques nous a amené à évaluer les effets de la modulation pharmacologique de la fréquence cardiaque sur le couplage contraction-relaxation. Ainsi la réduction sélective de la fréquence cardiaque par l'administration d'ivabradine, un inhibiteur des canaux If, a réduit significativement la durée de ces deux phases et favorisé le remplissage. Cependant, cette normalisation n'était qu'apparente puisque le ratio entre la contraction et la relaxation isovolumiques restait augmenté à J28, en défaveur de la contraction isovolumique.En conclusion, le développement d'une dysfonction diastolique avec une éjection préservée s'accompagne d'une dysfonction systolique qui entrave une réponse adéquate du myocarde à un stress dans un contexte d'hypertension chronique. / Approximately 20 millions individuals in the world experience heart failure symptoms; heart failure prevalence is continuously rising with population aging. Left ventricular function evaluation by the ejection fraction allows distinguishing two different patient sets: one with and one other without ejection fraction alteration, respectively named Heart Failure with Reduced Ejection Fraction (HF-rEF) and Heart Failure with Preserved Ejection Fraction (HF-pEF). It is unknown if these two clinical presentations represent two different pathologies or two manifestations of the same clinical entity. HF-pEF is found in about 40-50% of patients with heart failure and its evolution is similar to that of patients with HF-rEF.However, several conceptual difficulties deal with the HFpEF: on one hand, talking about preserved ejection fraction implies the knowledge of its basal value; on the other, the normality needs to be established. Moreover, considering the heart either as a hemodynamic pump or as a muscular pump may modify the understanding of HFpEF physiopathology.We therefore set up a swine model of diastolic dysfunction with preserved ejection induced by chronic hypertension, which was obtained by continuous perfusion of angiotensin II during 28 days. In these conditions, we clearly demonstrated a LV function impairment, while the ejection phase parameters remained preserved. The LV impairment is demonstrated by: 1) the paradox increase of the relative durations of isovolumic contraction and relaxation; 2) the blunted responses of the isovolumic phases of cardiac cycle to heart rate augmentation and cardiac inotropisme; 3) a straight relationship between these two isovolumic phases (contraction-relaxation relationship).The mismatch between the heart rate and the isovolumic phases behaviour led us to investigate the possible effects of the heart rate pharmacological modulation on the contraction-relaxation coupling. The selective reduction of the heart rate by ivabradine administration (a selective If channel inhibitor) was able to significantly reduce the isovolumic contraction and relaxation phases' durations, thus improving filling phase dynamics. Anyway, this “normalisation” was only apparent, because the contraction to relaxation ratio was increased at day 28, to the detriment of the isovolumic contraction.In conclusion, chronic hypertension induces a diastolic dysfunction with a preserved ejection fraction paralleled by a systolic dysfunction which is responsible of a blunted myocardial response to stress.

Uma nutrição maternal rica em lipídios pode causar prejuízos no desenvolvimento e na vida adulta dos descendentes, como elevado risco de desenvolver alterações metabólicas e obesidade, e também parece alterar a sinalização central por opióides. Porém, estudos realizados a fim de investigar a influência da dieta hiperlipídica (HF) materna sobre o comportamento materno e o desenvolvimento da prole não são conclusivos. Este trabalho investigou a influência da dieta HF sobre a interação mãe-filhote, em duas gerações, e os efeitos imediatos e tardios sobre a prole, relacionando-os ao sistema opióide. As mães HF apresentaram prejuízos na ejeção do leite e maior expressão dos receptores opióides no hipotálamo. No geral, os descendentes HF apresentaram elevados níveis de colesterol, baixa leptina plasmática, maior expressão de peptídeos relacionados à ingestão alimentar, e menor peso. Portanto, o consumo materno de dieta HF causou alterações metabólicas, comportamentais e na expressão gênica na mãe e nos descendentes, mesmo que esses animais não tenham se tornado obesos. / A maternal nutrition high in fat may impair offspring development and adulthood, increasing the risk to develop metabolic alterations and obesity, and may modify the opioids central signaling. However, studies investigating maternal high fat (HF) diet influences on maternal behavior and offspring development are inconclusive. This study aimed to evaluate the influences of a diet high in fat on mother-pup interaction, in two generations, and its early and late effects in the offspring, connecting them to the opioid system. HF dams show decreased milk ejections and higher expression of opioid receptors in the hypothalamus. Overall, HF offspring had higher cholesterol levels, less serum leptin, higher expression of peptides related to food intake, and were lighter. Therefore, maternal intake of HF diet promoted metabolic, behavioral and gene expression alterations in the mother and her offspring, even though these animals did not become obese.

Les ceintures de radiation correspondent à la région de la magnétosphère dans laquelle se trouvent les particules de hautes énergies. Le couplage entre le vent solaire et la magnétosphère donne lieu à des variations des flux de particules sur plusieurs ordres de grandeurs. L’objectif de cette thèse est d’observer et caractériser ces variations de flux d’électrons au passage de différents types d’événements tels que les régions d’interaction en co-rotation (CIRs) et les éjections de masse coronale interplanétaires (ICMEs). Pour cela, nous avons traité et analysé les données de plusieurs types: paramètres du vent solaire, indices géomagnétiques et flux d’électrons dans les ceintures de radiation. Dans les trois premiers chapitres, nous rendons compte de la complexité de l’environnement spatial Terrestre et présentons les différentes données utilisées. Les travaux de thèse sont ensuite organisés en quatre chapitres. Premièrement, nous utilisons les mesures des satellites NOAA-POES afin de caractériser les flux d’électrons dans les ceintures. Nous étudions ensuite les différences de variations de flux causées par les CIRs et les ICMEs en fonction de l’énergie des électrons et du paramètre L*. Après avoir montré le fort lien entre les intensités d’orages magnétiques et les variations de flux, nous nous focalisons sur les ICMEs et la variabilité des orages qu’elles causent. Enfin, nous insistons sur l’importance des enchaînements d’événements. Après avoir quantifié la forte tendance qu’ont les ICMEs à former des séquences, nous réalisons une étude statistique sur les orages qu’elles causent, puis trois études de cas afin d’illustrer leurs effets sur les ceintures. / The radiation belts are the toroidal region within the inner magnetosphere where high energetic particles are located. The coupling between the solar wind and the magnetosphere leads to strong variations of particle fluxes that can therefore increase or decrease over several orders of magnitude. The aim of this thesis is to observe and characterize the variations of fluxes during the crossing of several types of events originating from the sun such as Corotating Interaction Regions (CIRs) and Interplanetary Coronal Mass Ejections (ICMEs). To do so, we processed and analyzed the data of various types : solar wind parameters, geomagnetic indices, and electron fluxes within the radiation belts. In the three first chapters, we report on the complexity of the Terrestrial space environment and we present the Solar-Terrestrial system and the data used. Then, our work is organized around four chapters. First, we characterized the electron fluxes within the radiation belts as measured by the NOAA-POES spacecrafts. Then, we studied the difference between the variations of fluxes caused by the CIRs and the ICMEs depending on the energy and the L* parameter. After establishing strong links between the intensity of magnetic storms and the variations of fluxes, we focused on the ICMEs and the variability of the related magnetic storms. Eventually, we emphasized the importance of the sequences of events. After quantifying the trend of the ICMEs to form sequences, we performed a statistical study on the magnetic storms caused by such sequences. Finally three study cases were performed in order to illustrate the various possible effects on the radiation belts.

Coronal mass ejections (CMEs) are some of the extraterrestrialevents most impactful to earth. Eorts to model and predict theireects have seen new possibilities in the two most recent decades dueto multiple new spacecrafts providing a wider range of data than everbefore. Models of these events suer from a number of inaccuracies,one of them being the density ratio between the CME and the ambientsolar wind. Since the arrival time for potentially harmful disturbancespredicted by models has been proved to be highly sensitive to thisparameter we therefore take care to set it as accurately as possible.Traditionally this value is either set to a default, justied by denitionand theory, or set to the density ratio between the bulk if the ejectedgas and the surrounding medium. A proposition has been made tomeasure density enhancement dierently, using a reference point at theshock wave preceding the CME for each event. This method strives toimprove arrival time predictions and was in this paper tested for onecoronal mass ejection event. Two runs if the model WSA-ENLIL+Conewas made; one with the default value of density enhancement, onewith a value determined through the revised method using coronographdata. Running the model with the revised value improved the predictedarrival time by moving it forwards in time by 4h, which was still tooearly. Other input data into the model run was then discussed as apossible cause of the remaining inaccuracy. / Koronamassutkastningar är ett av solfenomenen som påverkar jorden mest.Nya rymdfarkoster med instrument som satts i arbete de senaste två decenniernahar gett data som gjort det möjligt att modellera och förutse dessaevent till en högre precision än någonsin. Alla dessa modeller lider av någonform av felkälla, en av vilka är kvoten mellan densitet för massutkastningenoch den omgivande miljön. Eftersom förutsedda ankomsstider för potentielltskadliga störningar har visat sig vara särskilt känsliga för denna parameterså tar vi särskild hänsyn till att ange den så precist som möjligt. Vanligtvissätts detta värde till ett fast standardvärde, som anges av dess denitionoch bakomliggande teori, eller till kvoten mellan utkastningens bulk ochomgivningen. Ett förslag har dock lagts fram om att omdeniera parametern.Denna metod strävar efter att förbättra förutsedda ankomsttider ochhar i denna text testats för en koronamassutkastning. Två körningar avmodellen WSA-ENLIL+Cone gjordes; en med defaultvärdet för densitetsratiot,en med värdet satt genom mätning av empirisk cononagrafdata enligtden föreslagna metoden. Att köra modellen med den nya parametern förbättrade den förutsedda ankomsttiden genom att ytta den framåt i tidenmed 4 timmar, vilket fortfarande är för tidigt. Andra inputdata i modellendiskuterades då som möjliga orsaker till den återstående diskrepansen.

Le champ magnétique joue un rôle prédominant dans la couronne solaire tant au niveau des structures observables qu'au niveau des phénomènes dynamiques que sont les éruptions. Cependant, ce champ magnétique n'est pas directement accessible à trois dimensions mais peut être mesuré à la surface du soleil, appelée photosphère, sous forme de magnétogrammes vectoriels. En utilisant ces données et l'hypothèse que le champ magnétique est à l'équilibre magnétostatique (champ sans force), il est alors possible de reconstruire le champ magnétique dans la couronne. Cette technique de reconstruction a été appliquée à trois domaines différents de la physique solaire. Le premier mécanisme étudié est l'émergence d'une structure magnétique provenant des couches sub-photosphériques. Le champ magnétique a été reconstruit à partir de données me- surées par le télescope THEMIS en Septembre 2005 et nous avons montré que la structure sous-jacente à l'émergence était un tube de flux torsadé à l'équilibre dans la configuration pré- éruptive de la région active. Le deuxième travail porte sur la caractérisation de la structure magnétique supportant un filament solaire en Avril-Mai 2007. Les données de Hinode ont été utilisées et nous avons mis en évidence que la matière froide du filament était supportée par un tube de flux torsadé. Le dernier travail présente l'évolution du champ magnétique reconstruit d'une région active émergente et ayant produit une forte éruption. Ici aussi, un tube de flux torsadé a été mis en évidence par la séquence des reconstructions, montrant sa création et son expansion dû au phénomène d'émergence ainsi que sa disparition après qu'une éruption ait eu lieu dans cette région active. Différents mécanismes d'éruption sont discutés. Les travaux de cette thèse font donc clairement apparaître le rôle majeur des tubes de flux torsadé pour comprendre les différents domaines étudiés et approfondir les relations entre observations et théories.

Left ventricular (LV) volumes and ejection fraction (EF) are important predictors of cardiac morbidity and mortality. LV volumes provide valuable prognostic information which isparticularly useful in the selection of therapy or determination of the optimal time for surgery. Two-dimensional (2D) echocardiography is the most widely used non-invasive method forassessment of cardiac function, 2D echocardiography has however several limitations inmeasuring LV volumes and EF since the formulas for quantifications are based on geometricalassumptions. Three-dimensional (3D) echocardiography has been available for almost twodecades, although the use of this modality has not gained wide spread acceptance. 3D echocardiography can overcome the above mentioned limitation in LV volume and EF evaluation since it is not based on geometrical assumption. 3D echocardiography has been shownin several studies to be more accurate and reproducible with low inter- and intraobservervariability in comparison to 2D echocardiography regarding the measurements of LV volumesand EF. The overall aim of the thesis was to evaluate the feasibility and accuracy of 3D echocardiography based-methods in the clinical context. In Study I the feasibility of 3D echocardiography was investigated for determination of LV volumes and EF using parasternal, apical and subcostal approaches. The study demonstrated that the apical 3D echocardiography view offers superior visualization. Study II tested the possibility of creating flow-volume loops to differentiate patients with valvular abnormalities from normal subjects. There were significant differences in the pattern from flow-volume loops clearly separating the groups. In Study III the visual estimation, “eyeballing” of EF was evaluated with two- and tri-plane echocardiography in comparison to quantitative 3D echocardiography. The study confirmed that an experienced echocardiographer can, with a high level of agreement estimate EF both with two- and tri-plane echocardiography. Study IV exposed the high accuracy of stroke volume and cardiac output determination using a3D biplane technique by planimetrically tracing the left ventricular outflow tract and indicating that an assumption of circular left ventricular outflow tract is not reliable. In Study V, two 3D echocardiography modalities, single-beat and four-beat ECG-gated 3D echocardiography were evaluated in patients having sinus rhythm and atrial fibrillation. Thesingle-beat technique showed significantly lower inter-and intraobserver variability in LV volumes and EF measurements in patients having atrial fibrillation in comparison to four-beat ECG-gated acquisition due to absence of stitching artifact. All studies demonstrated good results suggesting 3D echocardiography to be a feasible andaccurate method in daily clinical settings. / degree of Medical DoctorQC 20100629

An experimental study on impaction of a single drop on solid surfaces was conducted to show the effects of particles on the impact process. The parameters were: volume fraction of particles (0 to 0.3), particle size (0.47 to 250 micron), and ratio of particle size to drop size (0.00017 to 0.074). The effect of particle volume fraction on the spreading process depended on impact speed and substrate. At low impact speed, particles had little effect on the spreading except for surfaces where the equilibrium contact angle was low. For high impact speed, the influence of particles on spreading can be described by the effective viscosity. The effect of particle size on the spreading process also depended on impact speed and substrate. At low impact speed, the drop did not have enough kinetic energy to overcome the energy barrier associated with the large particles. For particle-laden liquids, retraction was affected by particle parameters. When pure liquid drops retracted from the maximum spreading ratio, the retraction appeared to be symmetric around the point of impaction while retraction of the particle-laden drop was sometimes asymmetric. Rebounding on the Teflon film depended on impact speed, particle volume fraction, and particle size. The impact speed must reach a critical value for rebounding to occur. Bouncing results suggested that the probability of bouncing decreased as viscosity increased, impact speed increased, and surface tension decreased. The non-wetting behavior and bouncing probably involved an air layer between the surface and the drop. When a low-velocity liquid drop impacts on a surface, ejection of a secondary drop from the top of the impacting drop was sometimes observed. When Renardy et al.'s (2003) criterion for the range of velocities for existence of a capillary wave was applied to for a 3.2-mm water drop; the range was between 0.2 to 1.5 m/s. However, drop ejection was observed at lower impact speed. When apparent viscosity of the particle-laden liquid obtained from Krieger's equation (1972) was used in the pure liquid models for predicting the maximum spreading ratio, good agreement between model predictions and experimental results was obtained when Park et al's model (2003) was used.